From 1da2bd6e1a06eab2ebd6ec4991a7aac479f2917e Mon Sep 17 00:00:00 2001
From: Chris Pulman <chris.pulman@yahoo.com>
Date: Sun, 16 May 2021 19:02:07 +0100
Subject: [PATCH] Update For Property Binding to make it easier to use Nullable
 ViewModels and ViewModel Properties (#2759)

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 @@ public interface IPropertyBinderImplementation : IEnableLogger
         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 @@ public interface IPropertyBinderImplementation : IEnableLogger
         /// <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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
             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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
         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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
                 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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
         /// <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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
                 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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
 
             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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
                 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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
         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 @@ bool ViewToVmFunc(TVProp vValue, out TVMProp vmValue)
                     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 @@ static PropertyBindingMixins()
         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 @@ static PropertyBindingMixins()
         /// <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 =>