From e138bc8896cad94b4bd1b2176eef17a72d323606 Mon Sep 17 00:00:00 2001
From: Chris Pulman <chris.pulman@yahoo.com>
Date: Sun, 16 May 2021 16:29:51 +0100
Subject: [PATCH] Update For Property Binding to make it easier to use Nullable
 ViewModels and ViewModel Properties

Updated Bind, OneWayBind and BindTo to allow nullable properties to be selected with less decorators.
Sub properties will still require ! and ? operators as required.
The Aim is to have less of an impact to those users upgrading older code.
---
 ...provalTests.ReactiveUI.net472.approved.txt | 36 +++++------
 ...provalTests.ReactiveUI.net5.0.approved.txt | 36 +++++------
 ...ests.ReactiveUI.netcoreapp3.1.approved.txt | 36 +++++------
 .../windows-xaml/PropertyBindingTest.cs       | 62 +++++++++----------
 .../Property/IPropertyBinderImplementation.cs | 18 +++---
 .../Property/PropertyBinderImplementation.cs  | 56 ++++++++---------
 .../Property/PropertyBindingMixins.cs         | 26 ++++----
 7 files changed, 132 insertions(+), 138 deletions(-)

diff --git a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt
index b4a66abcd1..66195a7794 100644
--- a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt
+++ b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt
@@ -234,25 +234,25 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor
         ;
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor
         ;
-        System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> propertyExpression, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> propertyExpression, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class
         ;
-        ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor
         ;
-        ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor
         ;
@@ -492,21 +492,21 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> propertyExpression, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> propertyExpression, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class { }
-        public ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        public ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
     }
@@ -515,33 +515,33 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
+        [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public static System.IDisposable BindTo<TValue, TTarget, TTValue>(this System.IObservable<TValue> @this, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> property, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public static System.IDisposable BindTo<TValue, TTarget, TTValue>(this System.IObservable<TValue> @this, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> property, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class { }
-        public static ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        public static ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public static ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
     }
diff --git a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt
index b9cee75035..9f28cb433a 100644
--- a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt
+++ b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt
@@ -234,21 +234,21 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
-        System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> propertyExpression, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> propertyExpression, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class;
-        ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
-        ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
     }
@@ -487,21 +487,21 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> propertyExpression, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> propertyExpression, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class { }
-        public ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        public ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
     }
@@ -510,33 +510,33 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
+        [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public static System.IDisposable BindTo<TValue, TTarget, TTValue>(this System.IObservable<TValue> @this, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> property, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public static System.IDisposable BindTo<TValue, TTarget, TTValue>(this System.IObservable<TValue> @this, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> property, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class { }
-        public static ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        public static ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public static ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
     }
diff --git a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt
index 2dd1be270f..1102562a15 100644
--- a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt
+++ b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt
@@ -232,21 +232,21 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
-        System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> propertyExpression, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> propertyExpression, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class;
-        ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
-        ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor;
     }
@@ -485,21 +485,21 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> propertyExpression, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public System.IDisposable BindTo<TValue, TTarget, TTValue>(System.IObservable<TValue> observedChange, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> propertyExpression, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class { }
-        public ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        public ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(TViewModel? viewModel, TView view, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
     }
@@ -508,33 +508,33 @@ namespace ReactiveUI
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
+        [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp> viewToVmConverter)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, System.Func<TVMProp?, TVProp> vmToViewConverter, System.Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
         [return: System.Runtime.CompilerServices.TupleElementNames(new string?[]?[] {
                 "view",
                 "isViewModel"})]
-        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, System.ValueTuple<object?, bool>> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, System.IObservable<TDontCare>? signalViewUpdate, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null, ReactiveUI.IBindingTypeConverter? viewToVMConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public static System.IDisposable BindTo<TValue, TTarget, TTValue>(this System.IObservable<TValue> @this, TTarget target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue>> property, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public static System.IDisposable BindTo<TValue, TTarget, TTValue>(this System.IObservable<TValue> @this, TTarget? target, System.Linq.Expressions.Expression<System.Func<TTarget, TTValue?>> property, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget :  class { }
-        public static ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp, TOut> selector)
+        public static ReactiveUI.IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TOut>> viewProperty, System.Func<TProp?, TOut> selector)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
-        public static ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
+        public static ReactiveUI.IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(this TView view, TViewModel? viewModel, System.Linq.Expressions.Expression<System.Func<TViewModel, TVMProp?>> vmProperty, System.Linq.Expressions.Expression<System.Func<TView, TVProp>> viewProperty, object? conversionHint = null, ReactiveUI.IBindingTypeConverter? vmToViewConverterOverride = null)
             where TViewModel :  class
             where TView :  class, ReactiveUI.IViewFor { }
     }
diff --git a/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs b/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs
index 3a49cac01d..3b28e4a8be 100644
--- a/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs
+++ b/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs
@@ -30,7 +30,7 @@ public class PropertyBindingTest
         [UseInvariantCulture]
         public void TwoWayBindWithFuncConvertersSmokeTest()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             var fixture = new PropertyBinderImplementation();
 
@@ -58,7 +58,7 @@ public void TwoWayBindWithFuncConvertersSmokeTest()
         [Fact]
         public void TwoWayBindSmokeTest()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             var fixture = new PropertyBinderImplementation();
 
@@ -86,7 +86,7 @@ public void TwoWayBindSmokeTest()
         [Fact]
         public void TypeConvertedTwoWayBindSmokeTest()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             var fixture = new PropertyBinderImplementation();
 
@@ -152,10 +152,10 @@ public void TypeConvertedTwoWayBindSmokeTest()
         [Fact]
         public void BindingIntoModelObjects()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
-            view.OneWayBind(view.ViewModel, x => x!.Model!.AnotherThing, x => x.SomeTextBox.Text);
+            view.OneWayBind(view.ViewModel, x => x.Model!.AnotherThing, x => x.SomeTextBox.Text);
             Assert.Equal("Baz", view.SomeTextBox.Text);
         }
 
@@ -165,7 +165,7 @@ public void BindingIntoModelObjects()
         [Fact]
         public void ViewModelNullableToViewNonNullable()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.Bind(view.ViewModel, x => x.NullableDouble, x => x.FakeControl.JustADouble);
@@ -187,7 +187,7 @@ public void ViewModelNullableToViewNonNullable()
         [Fact]
         public void ViewModelNonNullableToViewNullable()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.Bind(view.ViewModel, x => x.JustADouble, x => x.FakeControl.NullableDouble);
@@ -209,7 +209,7 @@ public void ViewModelNonNullableToViewNullable()
         [Fact]
         public void ViewModelNullableToViewNullable()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.Bind(view.ViewModel, x => x.NullableDouble, x => x.FakeControl.NullableDouble);
@@ -231,7 +231,7 @@ public void ViewModelNullableToViewNullable()
         [Fact]
         public void ViewModelIndexerToView()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.OneWayBind(view.ViewModel, x => x.SomeCollectionOfStrings[0], x => x.SomeTextBox.Text);
@@ -244,7 +244,7 @@ public void ViewModelIndexerToView()
         [Fact]
         public void ViewModelIndexerToViewChanges()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.OneWayBind(view.ViewModel, x => x.SomeCollectionOfStrings[0], x => x.SomeTextBox.Text);
@@ -261,7 +261,7 @@ public void ViewModelIndexerToViewChanges()
         [Fact]
         public void ViewModelIndexerPropertyToView()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.OneWayBind(view.ViewModel, x => x.SomeCollectionOfStrings[0].Length, x => x.SomeTextBox.Text);
@@ -274,14 +274,14 @@ public void ViewModelIndexerPropertyToView()
         [Fact]
         public void OneWayBindShouldntInitiallySetToNull()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = null };
 
-            view.OneWayBind(vm, x => x!.Model!.AnotherThing, x => x.FakeControl.NullHatingString);
+            view.OneWayBind(vm, x => x.Model!.AnotherThing, x => x.FakeControl.NullHatingString);
             Assert.Equal(string.Empty, view.FakeControl.NullHatingString);
 
             view.ViewModel = vm;
-            Assert.Equal(vm!.Model!.AnotherThing, view.FakeControl.NullHatingString);
+            Assert.Equal(vm.Model!.AnotherThing, view.FakeControl.NullHatingString);
         }
 
         /// <summary>
@@ -290,7 +290,7 @@ public void OneWayBindShouldntInitiallySetToNull()
         [Fact]
         public void BindToTypeConversionSmokeTest()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = null };
 
             Assert.Equal(string.Empty, view.FakeControl.NullHatingString);
@@ -312,7 +312,7 @@ public void BindToNullShouldThrowHelpfulError()
 
             Assert.Throws<ArgumentNullException>(() =>
                  view.WhenAnyValue(x => x.FakeControl!.NullHatingString!)
-                     .BindTo(view!.ViewModel!, x => x!.Property1));
+                     .BindTo(view.ViewModel, x => x.Property1));
         }
 
         /// <summary>
@@ -321,7 +321,7 @@ public void BindToNullShouldThrowHelpfulError()
         [Fact]
         public void TwoWayBindToSelectedItemOfItemsControl()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             view.FakeItemsControl.ItemsSource = new ObservableCollectionExtended<string>(new[] { "aaa", "bbb", "ccc" });
 
@@ -343,7 +343,7 @@ public void TwoWayBindToSelectedItemOfItemsControl()
         [Fact]
         public void ItemsControlShouldGetADataTemplate()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             Assert.Null(view.FakeItemsControl.ItemTemplate);
@@ -358,7 +358,7 @@ public void ItemsControlShouldGetADataTemplate()
         [Fact]
         public void ItemsControlWithDisplayMemberPathSetShouldNotGetADataTemplate()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             view.FakeItemsControl.DisplayMemberPath = "Bla";
 
@@ -374,7 +374,7 @@ public void ItemsControlWithDisplayMemberPathSetShouldNotGetADataTemplate()
         [Fact]
         public void ItemsControlShouldGetADataTemplateInBindTo()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             Assert.Null(view.FakeItemsControl.ItemTemplate);
@@ -393,7 +393,7 @@ public void ItemsControlShouldGetADataTemplateInBindTo()
         [Fact]
         public void BindingToItemsControl()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.OneWayBind(view.ViewModel, x => x.SomeCollectionOfStrings, x => x.FakeItemsControl.ItemsSource);
@@ -408,7 +408,7 @@ public void BindingToItemsControl()
         [Fact]
         public void OneWayBindConverter()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             var fixture = new PropertyBinderImplementation();
             fixture.OneWayBind(vm, view, x => x.JustABoolean, x => x.SomeTextBox.IsEnabled, s => s);
@@ -421,7 +421,7 @@ public void OneWayBindConverter()
         [Fact]
         public void OneWayBindWithNullStartingValueToNonNullValue()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.OneWayBind(vm, x => x.Property1, x => x.SomeTextBox.Text);
@@ -437,7 +437,7 @@ public void OneWayBindWithNullStartingValueToNonNullValue()
         [Fact]
         public void OneWayBindWithNonNullStartingValueToNullValue()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             vm.Property1 = "Baz";
@@ -455,7 +455,7 @@ public void OneWayBindWithNonNullStartingValueToNullValue()
         [Fact]
         public void OneWayBindWithSelectorAndNonNullStartingValueToNullValue()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.OneWayBind(vm, x => x.Model, x => x.SomeTextBox.Text, x => x?.AnotherThing);
@@ -473,7 +473,7 @@ public void OneWayBindInitialViewModelShouldBeGarbageCollectedWhenOverwritten()
         {
             static (IDisposable?, WeakReference) GetWeakReference()
             {
-                var vm = new PropertyBindViewModel();
+                PropertyBindViewModel? vm = new();
                 var view = new PropertyBindView { ViewModel = vm };
                 var weakRef = new WeakReference(vm);
                 var disp = view.OneWayBind(vm, x => x.Property1, x => x.SomeTextBox.Text);
@@ -496,7 +496,7 @@ public void OneWayBindInitialViewModelShouldBeGarbageCollectedWhenOverwritten()
         [Fact]
         public void BindToWithNullStartingValueToNonNullValue()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.WhenAnyValue(x => x.ViewModel!.Property1)
@@ -513,7 +513,7 @@ public void BindToWithNullStartingValueToNonNullValue()
         [Fact]
         public void BindToWithNonNullStartingValueToNullValue()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             vm.Property1 = "Baz";
@@ -532,7 +532,7 @@ public void BindToWithNonNullStartingValueToNullValue()
         [Fact]
         public void BindExpectsConverterFuncsToNotBeNull()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
             var fixture = new PropertyBinderImplementation();
 
@@ -548,7 +548,7 @@ public void BindExpectsConverterFuncsToNotBeNull()
         [Fact]
         public void BindWithFuncShouldWorkAsExtensionMethodSmokeTest()
         {
-            var vm = new PropertyBindViewModel();
+            PropertyBindViewModel? vm = new();
             var view = new PropertyBindView { ViewModel = vm };
 
             view.Bind(vm, x => x.JustADecimal, x => x.SomeTextBox.Text, d => d.ToString(CultureInfo.InvariantCulture), decimal.Parse);
@@ -562,7 +562,7 @@ public void BindInitialViewModelShouldBeGarbageCollectedWhenOverwritten()
         {
             static (IDisposable?, WeakReference) GetWeakReference()
             {
-                var vm = new PropertyBindViewModel();
+                PropertyBindViewModel? vm = new();
                 var view = new PropertyBindView { ViewModel = vm };
                 var weakRef = new WeakReference(vm);
                 var disp = view.Bind(vm, x => x.Property1, x => x.SomeTextBox.Text);
diff --git a/src/ReactiveUI/Bindings/Property/IPropertyBinderImplementation.cs b/src/ReactiveUI/Bindings/Property/IPropertyBinderImplementation.cs
index 6406ec8356..d130b27c7b 100644
--- a/src/ReactiveUI/Bindings/Property/IPropertyBinderImplementation.cs
+++ b/src/ReactiveUI/Bindings/Property/IPropertyBinderImplementation.cs
@@ -68,7 +68,7 @@ public interface IPropertyBinderImplementation : IEnableLogger
         IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(
                 TViewModel? viewModel,
                 TView view,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 IObservable<TDontCare>? signalViewUpdate,
                 object? conversionHint,
@@ -125,11 +125,11 @@ public interface IPropertyBinderImplementation : IEnableLogger
         IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(
                 TViewModel? viewModel,
                 TView view,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 IObservable<TDontCare>? signalViewUpdate,
-                Func<TVMProp, TVProp> vmToViewConverter,
-                Func<TVProp, TVMProp> viewToVmConverter)
+                Func<TVMProp?, TVProp> vmToViewConverter,
+                Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel : class
             where TView : class, IViewFor;
 
@@ -175,7 +175,7 @@ public interface IPropertyBinderImplementation : IEnableLogger
         IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(
                 TViewModel? viewModel,
                 TView view,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 object? conversionHint,
                 IBindingTypeConverter? vmToViewConverterOverride = null)
@@ -216,9 +216,9 @@ IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(
         IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(
             TViewModel? viewModel,
             TView view,
-            Expression<Func<TViewModel, TProp>> vmProperty,
+            Expression<Func<TViewModel, TProp?>> vmProperty,
             Expression<Func<TView, TOut>> viewProperty,
-            Func<TProp, TOut> selector)
+            Func<TProp?, TOut> selector)
             where TViewModel : class
             where TView : class, IViewFor;
 
@@ -248,8 +248,8 @@ IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(
         /// <returns>An object that when disposed, disconnects the binding.</returns>
         IDisposable BindTo<TValue, TTarget, TTValue>(
             IObservable<TValue> observedChange,
-            TTarget target,
-            Expression<Func<TTarget, TTValue>> propertyExpression,
+            TTarget? target,
+            Expression<Func<TTarget, TTValue?>> propertyExpression,
             object? conversionHint,
             IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget : class;
diff --git a/src/ReactiveUI/Bindings/Property/PropertyBinderImplementation.cs b/src/ReactiveUI/Bindings/Property/PropertyBinderImplementation.cs
index 84ce009b14..eda407f2cf 100644
--- a/src/ReactiveUI/Bindings/Property/PropertyBinderImplementation.cs
+++ b/src/ReactiveUI/Bindings/Property/PropertyBinderImplementation.cs
@@ -58,7 +58,7 @@ static PropertyBinderImplementation()
         public IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(
                 TViewModel? viewModel,
                 TView view,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 IObservable<TDontCare>? signalViewUpdate,
                 object? conversionHint,
@@ -76,27 +76,21 @@ static PropertyBinderImplementation()
                     $"Can't two-way convert between {typeof(TVMProp)} and {typeof(TVProp)}. To fix this, register a IBindingTypeConverter or call the version with the converter Func.");
             }
 
-#pragma warning disable CS8601 // Possible null reference assignment.
-            bool VmToViewFunc(TVMProp vmValue, out TVProp vValue)
+            bool VmToViewFunc(TVMProp? vmValue, out TVProp vValue)
             {
                 var result = vmToViewConverter.TryConvert(vmValue, typeof(TVProp), conversionHint, out object? tmp);
 
-#pragma warning disable CS8605 // Unboxing a possibly null value.
-                vValue = result && tmp != null ? (TVProp)tmp : default;
-#pragma warning restore CS8605 // Unboxing a possibly null value.
+                vValue = result && tmp != null ? (TVProp)tmp : default!;
                 return result;
             }
 
-            bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
+            bool ViewToVmFunc(TVProp vValue, out TVMProp? vmValue)
             {
-                var result = viewToVMConverter.TryConvert(vValue, typeof(TVMProp), conversionHint, out object? tmp);
+                var result = viewToVMConverter.TryConvert(vValue, typeof(TVMProp?), conversionHint, out object? tmp);
 
-#pragma warning disable CS8605 // Unboxing a possibly null value.
-                vmValue = result && tmp != null ? (TVMProp)tmp : default;
-#pragma warning restore CS8605 // Unboxing a possibly null value.
+                vmValue = result && tmp != null ? (TVMProp?)tmp : default;
                 return result;
             }
-#pragma warning restore CS8601 // Possible null reference assignment.
 
             return BindImpl(viewModel, view, vmProperty, viewProperty, signalViewUpdate, VmToViewFunc, ViewToVmFunc);
         }
@@ -105,11 +99,11 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
         public IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(
                 TViewModel? viewModel,
                 TView view,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 IObservable<TDontCare>? signalViewUpdate,
-                Func<TVMProp, TVProp> vmToViewConverter,
-                Func<TVProp, TVMProp> viewToVmConverter)
+                Func<TVMProp?, TVProp> vmToViewConverter,
+                Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel : class
             where TView : class, IViewFor
         {
@@ -133,13 +127,13 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
                 throw new ArgumentNullException(nameof(viewToVmConverter));
             }
 
-            bool VmToViewFunc(TVMProp vmValue, out TVProp vValue)
+            bool VmToViewFunc(TVMProp? vmValue, out TVProp vValue)
             {
                 vValue = vmToViewConverter(vmValue);
                 return true;
             }
 
-            bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
+            bool ViewToVmFunc(TVProp vValue, out TVMProp? vmValue)
             {
                 vmValue = viewToVmConverter(vValue);
                 return true;
@@ -152,7 +146,7 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
         public IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(
                 TViewModel? viewModel,
                 TView view,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 object? conversionHint = null,
                 IBindingTypeConverter? vmToViewConverterOverride = null)
@@ -172,7 +166,7 @@ public IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TV
             var vmExpression = Reflection.Rewrite(vmProperty.Body);
             var viewExpression = Reflection.Rewrite(viewProperty.Body);
             var viewType = viewExpression.Type;
-            var converter = vmToViewConverterOverride ?? GetConverterForTypes(typeof(TVMProp), viewType);
+            var converter = vmToViewConverterOverride ?? GetConverterForTypes(typeof(TVMProp?), viewType);
 
             if (converter == null)
             {
@@ -205,9 +199,9 @@ public IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TV
         public IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(
             TViewModel? viewModel,
             TView view,
-            Expression<Func<TViewModel, TProp>> vmProperty,
+            Expression<Func<TViewModel, TProp?>> vmProperty,
             Expression<Func<TView, TOut>> viewProperty,
-            Func<TProp, TOut> selector)
+            Func<TProp?, TOut> selector)
             where TViewModel : class
             where TView : class, IViewFor
         {
@@ -229,7 +223,7 @@ public IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(
                 return new ReactiveBinding<TView, TOut>(view, viewExpression, vmExpression, Observable.Empty<TOut>(), BindingDirection.OneWay, Disposable.Empty);
             }
 
-            var source = Reflection.ViewModelWhenAnyValue(viewModel, view, vmExpression).Cast<TProp>().Select(selector);
+            var source = Reflection.ViewModelWhenAnyValue(viewModel, view, vmExpression).Cast<TProp?>().Select(selector);
 
             var (disposable, obs) = BindToDirect<TView, TOut, TOut>(source, view, viewExpression);
 
@@ -239,8 +233,8 @@ public IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(
         /// <inheritdoc />
         public IDisposable BindTo<TValue, TTarget, TTValue>(
             IObservable<TValue> observedChange,
-            TTarget target,
-            Expression<Func<TTarget, TTValue>> propertyExpression,
+            TTarget? target,
+            Expression<Func<TTarget, TTValue?>> propertyExpression,
             object? conversionHint = null,
             IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget : class
@@ -263,7 +257,7 @@ public IDisposable BindTo<TValue, TTarget, TTValue>(
                 return Disposable.Empty;
             }
 
-            var converter = vmToViewConverterOverride ?? GetConverterForTypes(typeof(TValue), typeof(TTValue));
+            var converter = vmToViewConverterOverride ?? GetConverterForTypes(typeof(TValue), typeof(TTValue?));
 
             if (converter == null)
             {
@@ -272,7 +266,7 @@ public IDisposable BindTo<TValue, TTarget, TTValue>(
 
             var source = observedChange.SelectMany(x =>
             {
-                if (!converter.TryConvert(x, typeof(TTValue), conversionHint, out var tmp))
+                if (!converter.TryConvert(x, typeof(TTValue?), conversionHint, out var tmp))
                 {
                     return Observable<object>.Empty;
                 }
@@ -280,7 +274,7 @@ public IDisposable BindTo<TValue, TTarget, TTValue>(
                 return Observable.Return(tmp);
             });
 
-            var (disposable, _) = BindToDirect<TTarget, TTValue, object?>(source, target, viewExpression);
+            var (disposable, _) = BindToDirect<TTarget, TTValue?, object?>(source, target, viewExpression);
 
             return disposable;
         }
@@ -414,11 +408,11 @@ private bool EvalBindingHooks<TViewModel, TView>(TViewModel? viewModel, TView vi
         private IReactiveBinding<TView, (object? view, bool isViewModel)> BindImpl<TViewModel, TView, TVMProp, TVProp, TDontCare>(
             TViewModel? viewModel,
             TView view,
-            Expression<Func<TViewModel, TVMProp>> vmProperty,
+            Expression<Func<TViewModel, TVMProp?>> vmProperty,
             Expression<Func<TView, TVProp>> viewProperty,
             IObservable<TDontCare>? signalViewUpdate,
-            OutFunc<TVMProp, TVProp> vmToViewConverter,
-            OutFunc<TVProp, TVMProp> viewToVmConverter)
+            OutFunc<TVMProp?, TVProp> vmToViewConverter,
+            OutFunc<TVProp, TVMProp?> viewToVmConverter)
             where TView : class, IViewFor
             where TViewModel : class
         {
@@ -463,7 +457,7 @@ private bool EvalBindingHooks<TViewModel, TView>(TViewModel? viewModel, TView vi
                     return (true, vmAsView, isVm);
                 }
 
-                if (!viewToVmConverter(vValue, out TVMProp vAsViewModel) || EqualityComparer<TVMProp>.Default.Equals(vmValue, vAsViewModel))
+                if (!viewToVmConverter(vValue, out TVMProp? vAsViewModel) || EqualityComparer<TVMProp?>.Default.Equals(vmValue, vAsViewModel))
                 {
                     return (false, null, false);
                 }
diff --git a/src/ReactiveUI/Bindings/Property/PropertyBindingMixins.cs b/src/ReactiveUI/Bindings/Property/PropertyBindingMixins.cs
index 8edcb553d1..86a58059e0 100644
--- a/src/ReactiveUI/Bindings/Property/PropertyBindingMixins.cs
+++ b/src/ReactiveUI/Bindings/Property/PropertyBindingMixins.cs
@@ -60,7 +60,7 @@ static PropertyBindingMixins()
         public static IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp>(
                 this TView view,
                 TViewModel? viewModel,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 object? conversionHint = null,
                 IBindingTypeConverter? vmToViewConverterOverride = null,
@@ -125,7 +125,7 @@ static PropertyBindingMixins()
         public static IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(
                 this TView view,
                 TViewModel? viewModel,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 IObservable<TDontCare>? signalViewUpdate,
                 object? conversionHint = null,
@@ -169,10 +169,10 @@ static PropertyBindingMixins()
         public static IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp>(
             this TView view,
             TViewModel? viewModel,
-            Expression<Func<TViewModel, TVMProp>> vmProperty,
+            Expression<Func<TViewModel, TVMProp?>> vmProperty,
             Expression<Func<TView, TVProp>> viewProperty,
-            Func<TVMProp, TVProp> vmToViewConverter,
-            Func<TVProp, TVMProp> viewToVmConverter)
+            Func<TVMProp?, TVProp> vmToViewConverter,
+            Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel : class
             where TView : class, IViewFor => binderImplementation.Bind(viewModel, view, vmProperty, viewProperty, (IObservable<Unit>?)null, vmToViewConverter, viewToVmConverter);
 
@@ -219,11 +219,11 @@ static PropertyBindingMixins()
         public static IReactiveBinding<TView, (object? view, bool isViewModel)> Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(
             this TView view,
             TViewModel? viewModel,
-            Expression<Func<TViewModel, TVMProp>> vmProperty,
+            Expression<Func<TViewModel, TVMProp?>> vmProperty,
             Expression<Func<TView, TVProp>> viewProperty,
             IObservable<TDontCare>? signalViewUpdate,
-            Func<TVMProp, TVProp> vmToViewConverter,
-            Func<TVProp, TVMProp> viewToVmConverter)
+            Func<TVMProp?, TVProp> vmToViewConverter,
+            Func<TVProp, TVMProp?> viewToVmConverter)
             where TViewModel : class
             where TView : class, IViewFor =>
             binderImplementation.Bind(viewModel, view, vmProperty, viewProperty, signalViewUpdate, vmToViewConverter, viewToVmConverter);
@@ -267,7 +267,7 @@ static PropertyBindingMixins()
         public static IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMProp, TVProp>(
                 this TView view,
                 TViewModel? viewModel,
-                Expression<Func<TViewModel, TVMProp>> vmProperty,
+                Expression<Func<TViewModel, TVMProp?>> vmProperty,
                 Expression<Func<TView, TVProp>> viewProperty,
                 object? conversionHint = null,
                 IBindingTypeConverter? vmToViewConverterOverride = null)
@@ -314,9 +314,9 @@ public static IReactiveBinding<TView, TVProp> OneWayBind<TViewModel, TView, TVMP
         public static IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp, TOut>(
                 this TView view,
                 TViewModel? viewModel,
-                Expression<Func<TViewModel, TProp>> vmProperty,
+                Expression<Func<TViewModel, TProp?>> vmProperty,
                 Expression<Func<TView, TOut>> viewProperty,
-                Func<TProp, TOut> selector)
+                Func<TProp?, TOut> selector)
             where TViewModel : class
             where TView : class, IViewFor =>
             binderImplementation.OneWayBind(viewModel, view, vmProperty, viewProperty, selector);
@@ -347,8 +347,8 @@ public static IReactiveBinding<TView, TOut> OneWayBind<TViewModel, TView, TProp,
         /// <returns>An object that when disposed, disconnects the binding.</returns>
         public static IDisposable BindTo<TValue, TTarget, TTValue>(
             this IObservable<TValue> @this,
-            TTarget target,
-            Expression<Func<TTarget, TTValue>> property,
+            TTarget? target,
+            Expression<Func<TTarget, TTValue?>> property,
             object? conversionHint = null,
             IBindingTypeConverter? vmToViewConverterOverride = null)
             where TTarget : class =>