From 87bf80ab1cb778be3550829b559cf40c8f8bfdcd Mon Sep 17 00:00:00 2001 From: Bill Wagner Date: Mon, 15 Nov 2021 12:45:40 -0500 Subject: [PATCH 1/2] add config for required actions (#1213) See dotnet/docs#27056 for details. In order for an action to be required for PRs to be merged, required actions must be triggered. If filters prevent them from starting, the action stays in the "pending" state forever. --- .github/workflows/build-validation.yml | 25 +++++-------------------- 1 file changed, 5 insertions(+), 20 deletions(-) diff --git a/.github/workflows/build-validation.yml b/.github/workflows/build-validation.yml index 33300e6845..b144e62622 100644 --- a/.github/workflows/build-validation.yml +++ b/.github/workflows/build-validation.yml @@ -1,27 +1,12 @@ # This is a basic workflow to help you get started with Actions -name: Snippets 5000 +name: 'Snippets 5000' # Controls when the action will run. Triggers the workflow on push or pull request on: - pull_request: + pull_request_target: paths: - - "**.cs" - - "**.vb" - - "**.fs" - - "**.cpp" - - "**.h" - - "**.xaml" - - "**.razor" - - "**.cshtml" - - "**.vbhtml" - - "**.csproj" - - "**.vbproj" - - "**.fsproj" - - "**.vcxproj" - - "**.sln" - - "**global.json" - - "**snippets.5000.json" branches: '*' + types: [opened, synchronize, reopened] env: DOTNET_INSTALLER_CHANNEL: '6.0' @@ -30,8 +15,8 @@ env: # A workflow run is made up of one or more jobs that can run sequentially or in parallel jobs: - # This workflow contains a single job called "build" - build: + # This workflow contains a single job called "build snippets" + build-snippets: # The type of runner that the job will run on runs-on: windows-latest From c72a540a912d6587068384bed0a0f5503e685bfa Mon Sep 17 00:00:00 2001 From: Tris Shores <86677757+v-trisshores@users.noreply.github.com> Date: Mon, 15 Nov 2021 12:29:16 -0600 Subject: [PATCH 2/2] Content update - Dependency property callbacks and validation (user story 1878471) (#1210) * Add article, snippets, toc, and redirects * Minor edits * Add code comments --- .openpublishing.redirection.json | 8 + ...dency-property-callbacks-and-validation.md | 100 ++++++ ...ride-metadata-for-a-dependency-property.md | 2 +- .../csharp/App.xaml.cs | 11 + .../csharp/AssemblyInfo.cs | 10 + .../csharp/CodeSampleCsharp.csproj | 24 ++ .../csharp/MainWindow.xaml | 8 + .../csharp/MainWindow.xaml.cs | 322 ++++++++++++++++++ .../csharp/Properties/Resources.Designer.cs | 63 ++++ .../csharp/Properties/Resources.resx | 120 +++++++ .../csharp/app.xaml | 9 + .../vb/Application.xaml | 9 + .../vb/Application.xaml.vb | 6 + .../vb/AssemblyInfo.vb | 11 + .../vb/CodeSampleVb.vbproj | 22 ++ .../vb/MainWindow.xaml | 8 + .../vb/MainWindow.xaml.vb | 321 +++++++++++++++++ dotnet-desktop-guide/net/wpf/toc.yml | 2 + redirects_generator/definitions.json | 5 + 19 files changed, 1060 insertions(+), 1 deletion(-) create mode 100644 dotnet-desktop-guide/net/wpf/properties/dependency-property-callbacks-and-validation.md create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/App.xaml.cs create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/AssemblyInfo.cs create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/CodeSampleCsharp.csproj create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.Designer.cs create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.resx create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/app.xaml create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml.vb create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/AssemblyInfo.vb create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/CodeSampleVb.vbproj create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml create mode 100644 dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb diff --git a/.openpublishing.redirection.json b/.openpublishing.redirection.json index 5a9227402c..e52d2201de 100644 --- a/.openpublishing.redirection.json +++ b/.openpublishing.redirection.json @@ -548,6 +548,14 @@ { "source_path": "dotnet-desktop-guide/framework/wpf/properties/how-to-override-metadata-for-a-dependency-property.md", "redirect_url": "/dotnet/desktop/wpf/advanced/how-to-override-metadata-for-a-dependency-property?view=netframeworkdesktop-4.8" + }, + { + "source_path": "dotnet-desktop-guide/net/wpf/advanced/dependency-property-callbacks-and-validation.md", + "redirect_url": "/dotnet/desktop/wpf/properties/dependency-property-callbacks-and-validation?view=netdesktop-6.0" + }, + { + "source_path": "dotnet-desktop-guide/framework/wpf/properties/dependency-property-callbacks-and-validation.md", + "redirect_url": "/dotnet/desktop/wpf/advanced/dependency-property-callbacks-and-validation?view=netframeworkdesktop-4.8" } ] } diff --git a/dotnet-desktop-guide/net/wpf/properties/dependency-property-callbacks-and-validation.md b/dotnet-desktop-guide/net/wpf/properties/dependency-property-callbacks-and-validation.md new file mode 100644 index 0000000000..d7b77b8e45 --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/dependency-property-callbacks-and-validation.md @@ -0,0 +1,100 @@ +--- +title: "Dependency property callbacks and validation" +description: Learn how to implement dependency property callbacks and validation in Windows Presentation Foundation (WPF). +ms.date: "11/11/2021" +dev_langs: + - "csharp" + - "vb" +helpviewer_keywords: + - "dependency properties [WPF], validation" + - "coerce-value callbacks [WPF]" + - "callbacks [WPF], validation" + - "dependency properties [WPF], callbacks" + - "validation of dependency properties [WPF]" +--- + + +# Dependency property callbacks and validation (WPF .NET) + +This article describes how to define a dependency property and implement dependency property callbacks. The callbacks support value validation, value coercion, and other logic that's needed when a property value changes. + +## Prerequisites + +The article assumes a basic knowledge of dependency properties, and that you've read [Dependency properties overview](dependency-properties-overview.md). To follow the examples in this article, it helps if you're familiar with Extensible Application Markup Language (XAML) and know how to write WPF applications. + +## Validate-value callbacks + +Validate-value callbacks provide a way for you to check whether a new dependency property value is valid before it's applied by the property system. This callback raises an exception if the value doesn't meet the validation criteria. + +Validate-value callbacks can only be assigned to a dependency property once, during property registration. When registering a dependency property, you have the option to pass a reference to the method. Validate-value callbacks aren't part of property metadata, and can't be overridden. + +The effective value of a dependency property is its applied value. The effective value is determined through [property value precedence](dependency-property-value-precedence.md) when multiple property-based inputs exist. If a validate-value callback is registered for a dependency property, the property system will invoke its validate-value callback on value change, passing in the new value as an object. Within the callback, you can cast the value object back to the type registered with the property system, and then run your validation logic on it. The callback returns `true` if the value is valid for the property, otherwise `false`. + +If a validate-value callback returns `false`, an exception is raised and the new value is not applied. Application writers must be prepared to handle these exceptions. A common use of validate-value callbacks is validating enumeration values, or constraining numeric values when they represent measurements that have limits. Validate-value callbacks are invoked by the property system in different scenarios, including: + +- Object initialization, which applies a default value at creation time. +- Programmatic calls to . +- Metadata overrides that specify a new default value. + +Validate-value callbacks don't have a parameter that specifies the instance on which the new value is set. All instances of a `DependencyObject` share the same validate-value callback, so it can't be used to validate instance-specific scenarios. For more information, see . + +The following example shows how to prevent a property, typed as , being set to or . + +:::code language="csharp" source="./snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs" id="ValueValidationScenario"::: +:::code language="vb" source="./snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb" id="ValueValidationScenario"::: + +:::code language="csharp" source="./snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs" id="TestValueValidationScenario"::: +:::code language="vb" source="./snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb" id="TestValueValidationScenario"::: + +## Property-changed callbacks + +Property-changed callbacks notify you when the effective value of a dependency property has changed. + +Property-changed callbacks are part of dependency property metadata. If you derive from a class that defines a dependency property, or add your class as an owner of a dependency property, you can override the metadata. When overriding metadata, you have the option to provide a new reference. Use a property-changed callback to run logic that's needed when a property value changes. + +Unlike validate-value callbacks, property-changed callbacks have a parameter that specifies the instance on which the new value is set. The next example shows how a property-changed callback can use the `DependencyObject` instance reference to trigger coerce-value callbacks. + +## Coerce-value callbacks + +Coerce-value callbacks provide a way for you to get notified when the effective value of a dependency property is about to change, so that you can adjust the new value before it's applied. In addition to being triggered by the property system, you can invoke coerce-value callbacks from your code. + +Coerce-value callbacks are part of dependency property metadata. If you derive from a class that defines a dependency property, or add your class as an owner of a dependency property, you can override the metadata. When overriding the metadata, you have the option to provide a reference to a new . Use a coerce-value callback to evaluate new values and coerce them when necessary. The callback returns the coerced value if coercion occurred, otherwise it returns the unaltered new value. + +Similar to property-changed callbacks, coerce-value callbacks have a parameter that specifies the instance on which the new value is set. The next example shows how a coerce-value callback can use a `DependencyObject` instance reference to coerce property values. + +> [!NOTE] +> Default property values can't be coerced. A dependency property has its default value set on object initialization, or when you clear other values using . + +### Coerce-value and property-changed callbacks in combination + +You can create dependencies between properties on an element, by using coerce-value callbacks and property-changed callbacks in combination. For example, changes in one property force coercion or re-evaluation in another dependency property. The next example shows a common scenario: three dependency properties that respectively store the current value, minimum value, and maximum value of a UI element. If the maximum value changes so that it's less than the current value, the current value is then set to the new maximum value. And, if the minimum value changes so that it's greater than the current value, the current value is then set to the new minimum value. In the example, the for the current value explicitly invokes the for the minimum and maximum values. + +:::code language="csharp" source="./snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs" id="CurrentMinMaxScenario"::: +:::code language="vb" source="./snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb" id="CurrentMinMaxScenario"::: + +## Advanced callback scenarios + +### Constraints and desired values + +If a locally set value of a dependency property is changed through coercion, the unchanged locally set value is retained as the *desired value*. If the coercion is based on other property values, the property system will dynamically reevaluate the coercion whenever those other values change. Within the constraints of the coercion, the property system will apply a value that's closest to the desired value. Should the coercion condition no longer apply, the property system will restore the desired value—assuming no higher [precedence](/dotnet/desktop/wpf/properties/dependency-property-value-precedence#dependency-property-setting-precedence-list) value is active. The following example tests coercion in the current value, minimum value, and maximum value scenario. + +:::code language="csharp" source="./snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs" id="TestCurrentMinMaxScenario"::: +:::code language="vb" source="./snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb" id="TestCurrentMinMaxScenario"::: + +Fairly complex dependency scenarios can occur when you have multiple properties that are dependent on one another in a circular manner. Technically, there's nothing wrong with complex dependencies—except that a large number of re-evaluations can reduce performance. Also, complex dependencies that are exposed in the UI might confuse users. Treat and as unambiguously as possible, and don't over-constrain. + +### Cancel value changes + +By returning from a , you can reject a property value change. This mechanism is useful when a property value change is initiated asynchronously, but when it's applied is no longer valid for the current object state. Another scenario might be to selectively suppress a value change based on where it originated. In the following example, the `CoerceValueCallback` calls the method, which returns a structure with a enumeration that identifies the source of the new value. + +:::code language="csharp" source="./snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs" id="GetValueSourceScenario"::: +:::code language="vb" source="./snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb" id="GetValueSourceScenario"::: + +## See also + +- +- +- +- [Dependency properties overview](dependency-properties-overview.md) +- [Dependency property metadata](dependency-property-metadata.md) +- [Custom dependency properties](custom-dependency-properties.md) diff --git a/dotnet-desktop-guide/net/wpf/properties/how-to-override-metadata-for-a-dependency-property.md b/dotnet-desktop-guide/net/wpf/properties/how-to-override-metadata-for-a-dependency-property.md index 137b3d2274..6bbb81dd88 100644 --- a/dotnet-desktop-guide/net/wpf/properties/how-to-override-metadata-for-a-dependency-property.md +++ b/dotnet-desktop-guide/net/wpf/properties/how-to-override-metadata-for-a-dependency-property.md @@ -18,7 +18,7 @@ When you derive from a class that defines a dependency property, you inherit the ## Background -A class that defines a dependency property can specify its characteristics in or one of its derived types, such as . Examples of those characteristics are the default value and callback references that trigger on property change and/or coercion value change. Many classes that define dependency properties, specify property metadata during dependency property registration. When metadata isn't specified during registration, the WPF property system assigns a `PropertyMetadata` object with default values. Derived classes that inherit dependency properties through class inheritance have the option to override the original metadata of any dependency property. In this way, derived classes can selectively modify dependency property characteristics to meet class requirements. When calling , a derived class specifies its own type as the first parameter, and a metadata instance as the second parameter. +A class that defines a dependency property can specify its characteristics in or one of its derived types, such as . One of those characteristics is the default value of a dependency property. Many classes that define dependency properties, specify property metadata during dependency property registration. When metadata isn't specified during registration, the WPF property system assigns a `PropertyMetadata` object with default values. Derived classes that inherit dependency properties through class inheritance have the option to override the original metadata of any dependency property. In this way, derived classes can selectively modify dependency property characteristics to meet class requirements. When calling , a derived class specifies its own type as the first parameter, and a metadata instance as the second parameter. A derived class that overrides metadata on a dependency property must do so before the property is placed in use by the property system. A dependency property is placed in use when any instance of the class that registers the property is instantiated. To help meet this requirement, the derived class should call within its static constructor. Overriding the metadata of a dependency property after its owner type is instantiated won't raise exceptions, but will result in inconsistent behaviors in the property system. Also, a derived type can't override the metadata of a dependency property more than once, and attempts to do so will raise an exception. diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/App.xaml.cs b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/App.xaml.cs new file mode 100644 index 0000000000..bdad66d00e --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/App.xaml.cs @@ -0,0 +1,11 @@ +using System.Windows; + +namespace CodeSampleCsharp +{ + /// + /// Interaction logic for App.xaml + /// + public partial class App : Application + { + } +} diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/AssemblyInfo.cs b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/AssemblyInfo.cs new file mode 100644 index 0000000000..8b5504ecfb --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/AssemblyInfo.cs @@ -0,0 +1,10 @@ +using System.Windows; + +[assembly: ThemeInfo( + ResourceDictionaryLocation.None, //where theme specific resource dictionaries are located + //(used if a resource is not found in the page, + // or application resource dictionaries) + ResourceDictionaryLocation.SourceAssembly //where the generic resource dictionary is located + //(used if a resource is not found in the page, + // app, or any theme specific resource dictionaries) +)] diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/CodeSampleCsharp.csproj b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/CodeSampleCsharp.csproj new file mode 100644 index 0000000000..8824b2f16a --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/CodeSampleCsharp.csproj @@ -0,0 +1,24 @@ + + + + WinExe + net5.0-windows + true + + + + + True + True + Resources.resx + + + + + + ResXFileCodeGenerator + Resources.Designer.cs + + + + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml new file mode 100644 index 0000000000..6e69f732b4 --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml @@ -0,0 +1,8 @@ + + + + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs new file mode 100644 index 0000000000..bf1053d261 --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/MainWindow.xaml.cs @@ -0,0 +1,322 @@ +using System; +using System.Diagnostics; +using System.Windows; +using System.Windows.Controls; + +namespace CodeSampleCsharp +{ + /// + /// Interaction logic for MainWindow.xaml. + /// + public partial class MainWindow : Window + { + public MainWindow() => InitializeComponent(); + + public void RunTests(object sender, RoutedEventArgs e) + { + TestValidationBehavior(); + TestCoercionBehavior(); + TestGetValueSource(); + } + + // + public static void TestValidationBehavior() + { + Gauge1 gauge = new(); + + Debug.WriteLine($"Test value validation scenario:"); + + // Set allowed value. + gauge.CurrentReading = 5; + Debug.WriteLine($"Current reading: {gauge.CurrentReading}"); + + try + { + // Set disallowed value. + gauge.CurrentReading = double.PositiveInfinity; + } + catch (ArgumentException e) + { + Debug.WriteLine($"Exception thrown by ValidateValueCallback: {e.Message}"); + } + + Debug.WriteLine($"Current reading: {gauge.CurrentReading}"); + + // Current reading: 5 + // Exception thrown by ValidateValueCallback: '∞' is not a valid value for property 'CurrentReading'. + // Current reading: 5 + } + // + + // + public static void TestCoercionBehavior() + { + Gauge2 gauge = new() + { + // Set initial values. + MinReading = 0, + MaxReading = 10, + CurrentReading = 5 + }; + + Debug.WriteLine($"Test current/min/max values scenario:"); + + // Current reading is not coerced. + Debug.WriteLine($"Current reading: " + + $"{gauge.CurrentReading} (min: {gauge.MinReading}, max: {gauge.MaxReading})"); + + // Current reading is coerced to max value. + gauge.MaxReading = 3; + Debug.WriteLine($"Current reading: " + + $"{gauge.CurrentReading} (min: {gauge.MinReading}, max: {gauge.MaxReading})"); + + // Current reading is coerced, but tracking back to the desired value. + gauge.MaxReading = 4; + Debug.WriteLine($"Current reading: " + + $"{gauge.CurrentReading} (min: {gauge.MinReading}, max: {gauge.MaxReading})"); + + // Current reading reverts to the desired value. + gauge.MaxReading = 10; + Debug.WriteLine($"Current reading: " + + $"{gauge.CurrentReading} (min: {gauge.MinReading}, max: {gauge.MaxReading})"); + + // Current reading remains at the desired value. + gauge.MinReading = 5; + gauge.MaxReading = 5; + Debug.WriteLine($"Current reading: " + + $"{gauge.CurrentReading} (min: {gauge.MinReading}, max: {gauge.MaxReading})"); + + // Current reading: 5 (min=0, max=10) + // Current reading: 3 (min=0, max=3) + // Current reading: 4 (min=0, max=4) + // Current reading: 5 (min=0, max=10) + // Current reading: 5 (min=5, max=5) + } + // + + // + public static void TestGetValueSource() + { + Gauge3 gauge = new() + { + // The GetValueSource method sees the first + // locally set value as a default value (why?) + CurrentReading = 5 + }; + + Debug.WriteLine($"Test GetValueSource scenario:"); + + // Locally set value. + gauge.CurrentReading = 7; + + // Locally set value is rejected. + Debug.WriteLine($"Current reading: " + + $"{gauge.CurrentReading}"); + + // Current reading: 5 + } + // + } + + // + public class Gauge1 : Control + { + public Gauge1() : base() { } + + // Register a dependency property with the specified property name, + // property type, owner type, property metadata, and callbacks. + public static readonly DependencyProperty CurrentReadingProperty = + DependencyProperty.Register( + name: "CurrentReading", + propertyType: typeof(double), + ownerType: typeof(Gauge1), + typeMetadata: new FrameworkPropertyMetadata( + defaultValue: double.NaN, + flags: FrameworkPropertyMetadataOptions.AffectsMeasure), + validateValueCallback: new ValidateValueCallback(IsValidReading)); + + // CLR wrapper with get/set accessors. + public double CurrentReading + { + get => (double)GetValue(CurrentReadingProperty); + set => SetValue(CurrentReadingProperty, value); + } + + // Validate-value callback. + public static bool IsValidReading(object value) + { + double val = (double)value; + return !val.Equals(double.NegativeInfinity) && + !val.Equals(double.PositiveInfinity); + } + } + // + + // + public class Gauge2 : Control + { + public Gauge2() : base() { } + + // Register a dependency property with the specified property name, + // property type, owner type, property metadata, and callbacks. + public static readonly DependencyProperty CurrentReadingProperty = + DependencyProperty.Register( + name: "CurrentReading", + propertyType: typeof(double), + ownerType: typeof(Gauge2), + typeMetadata: new FrameworkPropertyMetadata( + defaultValue: double.NaN, + flags: FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback: new PropertyChangedCallback(OnCurrentReadingChanged), + coerceValueCallback: new CoerceValueCallback(CoerceCurrentReading) + ), + validateValueCallback: new ValidateValueCallback(IsValidReading) + ); + + // CLR wrapper with get/set accessors. + public double CurrentReading + { + get => (double)GetValue(CurrentReadingProperty); + set => SetValue(CurrentReadingProperty, value); + } + + // Validate-value callback. + public static bool IsValidReading(object value) + { + double val = (double)value; + return !val.Equals(double.NegativeInfinity) && !val.Equals(double.PositiveInfinity); + } + + // Property-changed callback. + private static void OnCurrentReadingChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e) + { + depObj.CoerceValue(MinReadingProperty); + depObj.CoerceValue(MaxReadingProperty); + } + + // Coerce-value callback. + private static object CoerceCurrentReading(DependencyObject depObj, object value) + { + Gauge2 gauge = (Gauge2)depObj; + double currentVal = (double)value; + currentVal = currentVal < gauge.MinReading ? gauge.MinReading : currentVal; + currentVal = currentVal > gauge.MaxReading ? gauge.MaxReading : currentVal; + return currentVal; + } + + // Register a dependency property with the specified property name, + // property type, owner type, property metadata, and callbacks. + public static readonly DependencyProperty MaxReadingProperty = DependencyProperty.Register( + name: "MaxReading", + propertyType: typeof(double), + ownerType: typeof(Gauge2), + typeMetadata: new FrameworkPropertyMetadata( + defaultValue: double.NaN, + flags: FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback: new PropertyChangedCallback(OnMaxReadingChanged), + coerceValueCallback: new CoerceValueCallback(CoerceMaxReading) + ), + validateValueCallback: new ValidateValueCallback(IsValidReading) + ); + + // CLR wrapper with get/set accessors. + public double MaxReading + { + get => (double)GetValue(MaxReadingProperty); + set => SetValue(MaxReadingProperty, value); + } + + // Property-changed callback. + private static void OnMaxReadingChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e) + { + depObj.CoerceValue(MinReadingProperty); + depObj.CoerceValue(CurrentReadingProperty); + } + + // Coerce-value callback. + private static object CoerceMaxReading(DependencyObject depObj, object value) + { + Gauge2 gauge = (Gauge2)depObj; + double maxVal = (double)value; + return maxVal < gauge.MinReading ? gauge.MinReading : maxVal; + } + + // Register a dependency property with the specified property name, + // property type, owner type, property metadata, and callbacks. + public static readonly DependencyProperty MinReadingProperty = DependencyProperty.Register( + name: "MinReading", + propertyType: typeof(double), + ownerType: typeof(Gauge2), + typeMetadata: new FrameworkPropertyMetadata( + defaultValue: double.NaN, + flags: FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback: new PropertyChangedCallback(OnMinReadingChanged), + coerceValueCallback: new CoerceValueCallback(CoerceMinReading) + ), + validateValueCallback: new ValidateValueCallback(IsValidReading)); + + // CLR wrapper with get/set accessors. + public double MinReading + { + get => (double)GetValue(MinReadingProperty); + set => SetValue(MinReadingProperty, value); + } + + // Property-changed callback. + private static void OnMinReadingChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs e) + { + depObj.CoerceValue(MaxReadingProperty); + depObj.CoerceValue(CurrentReadingProperty); + } + + // Coerce-value callback. + private static object CoerceMinReading(DependencyObject depObj, object value) + { + Gauge2 gauge = (Gauge2)depObj; + double minVal = (double)value; + return minVal > gauge.MaxReading ? gauge.MaxReading : minVal; + } + } + // + + public class Gauge3 : Control + { + public Gauge3() : base() { } + + // Register a dependency property with the specified property name, + // property type, owner type, property metadata, and callbacks. + public static readonly DependencyProperty CurrentReadingProperty = + DependencyProperty.Register( + name: "CurrentReading", + propertyType: typeof(double), + ownerType: typeof(Gauge3), + typeMetadata: new FrameworkPropertyMetadata( + defaultValue: double.NaN, + flags: FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback: null, + coerceValueCallback: new CoerceValueCallback(CoerceCurrentReading) + ) + ); + + // CLR wrapper with get/set accessors. + public double CurrentReading + { + get => (double)GetValue(CurrentReadingProperty); + set => SetValue(CurrentReadingProperty, value); + } + + // + // Coerce-value callback. + private static object CoerceCurrentReading(DependencyObject depObj, object value) + { + // Get value source. + ValueSource valueSource = + DependencyPropertyHelper.GetValueSource(depObj, CurrentReadingProperty); + + // Reject any property value change that's a locally set value. + return valueSource.BaseValueSource == BaseValueSource.Local ? + DependencyProperty.UnsetValue : value; + } + // + } +} diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.Designer.cs b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.Designer.cs new file mode 100644 index 0000000000..64552f96fd --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.Designer.cs @@ -0,0 +1,63 @@ +//------------------------------------------------------------------------------ +// +// This code was generated by a tool. +// Runtime Version:4.0.30319.42000 +// +// Changes to this file may cause incorrect behavior and will be lost if +// the code is regenerated. +// +//------------------------------------------------------------------------------ + +namespace CodeSampleCsharp.Properties { + using System; + + + /// + /// A strongly-typed resource class, for looking up localized strings, etc. + /// + // This class was auto-generated by the StronglyTypedResourceBuilder + // class via a tool like ResGen or Visual Studio. + // To add or remove a member, edit your .ResX file then rerun ResGen + // with the /str option, or rebuild your VS project. + [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")] + [global::System.Diagnostics.DebuggerNonUserCodeAttribute()] + [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()] + internal class Resources { + + private static global::System.Resources.ResourceManager resourceMan; + + private static global::System.Globalization.CultureInfo resourceCulture; + + [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")] + internal Resources() { + } + + /// + /// Returns the cached ResourceManager instance used by this class. + /// + [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)] + internal static global::System.Resources.ResourceManager ResourceManager { + get { + if (object.ReferenceEquals(resourceMan, null)) { + global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("CodeSampleCsharp.Properties.Resources", typeof(Resources).Assembly); + resourceMan = temp; + } + return resourceMan; + } + } + + /// + /// Overrides the current thread's CurrentUICulture property for all + /// resource lookups using this strongly typed resource class. + /// + [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)] + internal static global::System.Globalization.CultureInfo Culture { + get { + return resourceCulture; + } + set { + resourceCulture = value; + } + } + } +} diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.resx b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.resx new file mode 100644 index 0000000000..1af7de150c --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/Properties/Resources.resx @@ -0,0 +1,120 @@ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + text/microsoft-resx + + + 2.0 + + + System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 + + + System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 + + \ No newline at end of file diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/app.xaml b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/app.xaml new file mode 100644 index 0000000000..867d2f015f --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/csharp/app.xaml @@ -0,0 +1,9 @@ + + + + + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml new file mode 100644 index 0000000000..f225972592 --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml @@ -0,0 +1,9 @@ + + + + + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml.vb b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml.vb new file mode 100644 index 0000000000..084cbe917e --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/Application.xaml.vb @@ -0,0 +1,6 @@ +Class Application + + ' Application-level events, such as Startup, Exit, and DispatcherUnhandledException + ' can be handled in this file. + +End Class diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/AssemblyInfo.vb b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/AssemblyInfo.vb new file mode 100644 index 0000000000..025ee7271e --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/AssemblyInfo.vb @@ -0,0 +1,11 @@ +Imports System.Windows + +'The ThemeInfo attribute describes where any theme specific and generic resource dictionaries can be found. +'1st parameter: where theme specific resource dictionaries are located +'(used if a resource is not found in the page, +' or application resource dictionaries) + +'2nd parameter: where the generic resource dictionary is located +'(used if a resource is not found in the page, +'app, and any theme specific resource dictionaries) + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/CodeSampleVb.vbproj b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/CodeSampleVb.vbproj new file mode 100644 index 0000000000..c7ae1cc7ce --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/CodeSampleVb.vbproj @@ -0,0 +1,22 @@ + + + + WinExe + net5.0-windows + CodeSampleVb + true + + + + + + + + + + + + + + + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml new file mode 100644 index 0000000000..32dfaa962c --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml @@ -0,0 +1,8 @@ + + + + diff --git a/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb new file mode 100644 index 0000000000..a5d292afc0 --- /dev/null +++ b/dotnet-desktop-guide/net/wpf/properties/snippets/dependency-property-callbacks-and-validation/vb/MainWindow.xaml.vb @@ -0,0 +1,321 @@ +Namespace CodeSampleVb + + ' + ' Interaction logic for MainWindow.xaml. + ' + Partial Public Class MainWindow + Inherits Window + + Public Sub New() + InitializeComponent() + End Sub + + Public Sub RunTests(sender As Object, e As RoutedEventArgs) + TestValidationBehavior() + TestCoercionBehavior() + TestGetValueSource() + End Sub + + ' + Public Shared Sub TestValidationBehavior() + Dim gauge As New Gauge1() + + Debug.WriteLine($"Test value validation scenario:") + + ' Set allowed value. + gauge.CurrentReading = 5 + Debug.WriteLine($"Current reading: {gauge.CurrentReading}") + + Try + ' Set disallowed value. + gauge.CurrentReading = Double.PositiveInfinity + Catch e As ArgumentException + Debug.WriteLine($"Exception thrown by ValidateValueCallback: {e.Message}") + End Try + + Debug.WriteLine($"Current reading: {gauge.CurrentReading}") + + ' Current reading: 5 + ' Exception thrown by ValidateValueCallback: '∞' is not a valid value for property 'CurrentReading'. + ' Current reading 5 + End Sub + ' + + ' + Public Shared Sub TestCoercionBehavior() + + ' Set initial values. + Dim gauge As New Gauge2 With { + .MinReading = 0, + .MaxReading = 10, + .CurrentReading = 5 + } + + Debug.WriteLine($"Test current/min/max values scenario:") + + ' Current reading is not coerced. + Debug.WriteLine($"Current reading: " & + $"{gauge.CurrentReading} (min={gauge.MinReading}, max={gauge.MaxReading})") + + ' Current reading is coerced to max value. + gauge.MaxReading = 3 + Debug.WriteLine($"Current reading: " & + $"{gauge.CurrentReading} (min={gauge.MinReading}, max={gauge.MaxReading})") + + ' Current reading is coerced, but tracking back to the desired value. + gauge.MaxReading = 4 + Debug.WriteLine($"Current reading: " & + $"{gauge.CurrentReading} (min={gauge.MinReading}, max={gauge.MaxReading})") + + ' Current reading reverts to the desired value. + gauge.MaxReading = 10 + Debug.WriteLine($"Current reading: " & + $"{gauge.CurrentReading} (min={gauge.MinReading}, max={gauge.MaxReading})") + + ' Current reading remains at the desired value. + gauge.MinReading = 5 + gauge.MaxReading = 5 + Debug.WriteLine($"Current reading: " & + $"{gauge.CurrentReading} (min={gauge.MinReading}, max={gauge.MaxReading})") + + ' Current reading: 5 (min=0, max=10) + ' Current reading: 3 (min=0, max=3) + ' Current reading: 4 (min=0, max=4) + ' Current reading: 5 (min=0, max=10) + ' Current reading: 5 (min=5, max=5) + End Sub + ' + + ' + Public Shared Sub TestGetValueSource() + + Dim gauge As New Gauge3 With { + .CurrentReading = 5 + } + + Debug.WriteLine($"Test GetValueSource scenario:") + + ' Locally set value. + gauge.CurrentReading = 7 + + ' Locally set value is rejected. + Debug.WriteLine($"Current reading: " & + $"{gauge.CurrentReading}") + + ' Current reading: 5 + End Sub + ' + + End Class + + ' + Public Class Gauge1 + Inherits Control + + Public Sub New() + MyBase.New() + End Sub + + Public Shared ReadOnly CurrentReadingProperty As DependencyProperty = + DependencyProperty.Register( + name:="CurrentReading", + propertyType:=GetType(Double), + ownerType:=GetType(Gauge1), + typeMetadata:=New FrameworkPropertyMetadata( + defaultValue:=Double.NaN, + flags:=FrameworkPropertyMetadataOptions.AffectsMeasure), + validateValueCallback:=New ValidateValueCallback(AddressOf IsValidReading)) + + Public Property CurrentReading As Double + Get + Return GetValue(CurrentReadingProperty) + End Get + Set(value As Double) + SetValue(CurrentReadingProperty, value) + End Set + End Property + + Public Shared Function IsValidReading(value As Object) As Boolean + Dim val As Double = value + Return Not val.Equals(Double.NegativeInfinity) AndAlso + Not val.Equals(Double.PositiveInfinity) + End Function + + End Class + ' + + ' + Public Class Gauge2 + Inherits Control + + Public Sub New() + MyBase.New() + End Sub + + ' Register a dependency property with the specified property name, + ' property type, owner type, property metadata, And callbacks. + Public Shared ReadOnly CurrentReadingProperty As DependencyProperty = + DependencyProperty.Register( + name:="CurrentReading", + propertyType:=GetType(Double), + ownerType:=GetType(Gauge2), + typeMetadata:=New FrameworkPropertyMetadata( + defaultValue:=Double.NaN, + flags:=FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback:=New PropertyChangedCallback(AddressOf OnCurrentReadingChanged), + coerceValueCallback:=New CoerceValueCallback(AddressOf CoerceCurrentReading)), + validateValueCallback:=New ValidateValueCallback(AddressOf IsValidReading)) + + ' CLR wrapper with get/set accessors. + Public Property CurrentReading As Double + Get + Return GetValue(CurrentReadingProperty) + End Get + Set(value As Double) + SetValue(CurrentReadingProperty, value) + End Set + End Property + + ' Validate-value callback. + Public Shared Function IsValidReading(value As Object) As Boolean + Dim val As Double = value + Return Not val.Equals(Double.NegativeInfinity) AndAlso Not val.Equals(Double.PositiveInfinity) + End Function + + ' Property-changed callback. + Private Shared Sub OnCurrentReadingChanged(depObj As DependencyObject, e As DependencyPropertyChangedEventArgs) + depObj.CoerceValue(MinReadingProperty) + depObj.CoerceValue(MaxReadingProperty) + End Sub + + ' Coerce-value callback. + Private Shared Function CoerceCurrentReading(depObj As DependencyObject, value As Object) As Object + Dim gauge As Gauge2 = CType(depObj, Gauge2) + Dim currentVal As Double = value + currentVal = If(currentVal < gauge.MinReading, gauge.MinReading, currentVal) + currentVal = If(currentVal > gauge.MaxReading, gauge.MaxReading, currentVal) + Return currentVal + End Function + + ' + Public Shared ReadOnly MaxReadingProperty As DependencyProperty = + DependencyProperty.Register( + name:="MaxReading", + propertyType:=GetType(Double), + ownerType:=GetType(Gauge2), + typeMetadata:=New FrameworkPropertyMetadata( + defaultValue:=Double.NaN, + flags:=FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback:=New PropertyChangedCallback(AddressOf OnMaxReadingChanged), + coerceValueCallback:=New CoerceValueCallback(AddressOf CoerceMaxReading)), + validateValueCallback:=New ValidateValueCallback(AddressOf IsValidReading)) + + ' CLR wrapper with get/set accessors. + Public Property MaxReading As Double + Get + Return GetValue(MaxReadingProperty) + End Get + Set(value As Double) + SetValue(MaxReadingProperty, value) + End Set + End Property + + ' Property-changed callback. + Private Shared Sub OnMaxReadingChanged(depObj As DependencyObject, e As DependencyPropertyChangedEventArgs) + depObj.CoerceValue(MinReadingProperty) + depObj.CoerceValue(CurrentReadingProperty) + End Sub + + ' Coerce-value callback. + Private Shared Function CoerceMaxReading(depObj As DependencyObject, value As Object) As Object + Dim gauge As Gauge2 = CType(depObj, Gauge2) + Dim maxVal As Double = value + Return If(maxVal < gauge.MinReading, gauge.MinReading, maxVal) + End Function + + ' Register a dependency property with the specified property name, + ' property type, owner type, property metadata, And callbacks. + Public Shared ReadOnly MinReadingProperty As DependencyProperty = + DependencyProperty.Register( + name:="MinReading", + propertyType:=GetType(Double), + ownerType:=GetType(Gauge2), + typeMetadata:=New FrameworkPropertyMetadata( + defaultValue:=Double.NaN, + flags:=FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback:=New PropertyChangedCallback(AddressOf OnMinReadingChanged), + coerceValueCallback:=New CoerceValueCallback(AddressOf CoerceMinReading)), + validateValueCallback:=New ValidateValueCallback(AddressOf IsValidReading)) + + ' CLR wrapper with get/set accessors. + Public Property MinReading As Double + Get + Return GetValue(MinReadingProperty) + End Get + Set(value As Double) + SetValue(MinReadingProperty, value) + End Set + End Property + + ' Property-changed callback. + Private Shared Sub OnMinReadingChanged(depObj As DependencyObject, e As DependencyPropertyChangedEventArgs) + depObj.CoerceValue(MaxReadingProperty) + depObj.CoerceValue(CurrentReadingProperty) + End Sub + + ' Coerce-value callback. + Private Shared Function CoerceMinReading(depObj As DependencyObject, value As Object) As Object + Dim gauge As Gauge2 = CType(depObj, Gauge2) + Dim minVal As Double = value + Return If(minVal > gauge.MaxReading, gauge.MaxReading, minVal) + End Function + ' + + End Class + ' + + Public Class Gauge3 + Inherits Control + + Public Sub New() + MyBase.New() + End Sub + + ' Register a dependency property with the specified property name, + ' property type, owner type, property metadata, And callbacks. + Public Shared ReadOnly CurrentReadingProperty As DependencyProperty = + DependencyProperty.Register( + name:="CurrentReading", + propertyType:=GetType(Double), + ownerType:=GetType(Gauge3), + typeMetadata:=New FrameworkPropertyMetadata( + defaultValue:=Double.NaN, + flags:=FrameworkPropertyMetadataOptions.AffectsMeasure, + propertyChangedCallback:=Nothing, + coerceValueCallback:=New CoerceValueCallback(AddressOf CoerceCurrentReading))) + + ' CLR wrapper with get/set accessors. + Public Property CurrentReading As Double + Get + Return GetValue(CurrentReadingProperty) + End Get + Set(value As Double) + SetValue(CurrentReadingProperty, value) + End Set + End Property + + ' + ' Coerce-value callback. + Private Shared Function CoerceCurrentReading(depObj As DependencyObject, value As Object) As Object + ' Get value source. + Dim valueSource As ValueSource = + DependencyPropertyHelper.GetValueSource(depObj, CurrentReadingProperty) + + ' Reject any property value that's a locally set value. + Return If(valueSource.BaseValueSource = BaseValueSource.Local, DependencyProperty.UnsetValue, value) + End Function + ' + + End Class + +End Namespace diff --git a/dotnet-desktop-guide/net/wpf/toc.yml b/dotnet-desktop-guide/net/wpf/toc.yml index c695edaa85..055406d8c4 100644 --- a/dotnet-desktop-guide/net/wpf/toc.yml +++ b/dotnet-desktop-guide/net/wpf/toc.yml @@ -92,6 +92,8 @@ items: href: properties/custom-dependency-properties.md - name: Dependency property metadata href: properties/dependency-property-metadata.md + - name: Dependency property callbacks and validation + href: properties/dependency-property-callbacks-and-validation.md - name: Common tasks items: - name: Implement a dependency property diff --git a/redirects_generator/definitions.json b/redirects_generator/definitions.json index 02a4d99701..a4bfe064ad 100644 --- a/redirects_generator/definitions.json +++ b/redirects_generator/definitions.json @@ -373,6 +373,11 @@ "SourceUrl": "/dotnet/desktop/wpf/advanced/how-to-override-metadata-for-a-dependency-property?view=netframeworkdesktop-4.8", "TargetUrl": "/dotnet/desktop/wpf/properties/how-to-override-metadata-for-a-dependency-property?view=netdesktop-6.0" }, + { + "Redirect": "TwoWay", + "SourceUrl": "/dotnet/desktop/wpf/advanced/dependency-property-callbacks-and-validation?view=netframeworkdesktop-4.8", + "TargetUrl": "/dotnet/desktop/wpf/properties/dependency-property-callbacks-and-validation?view=netdesktop-6.0" + }, // Systems - XAML {