Content update - How to create a custom routed event (user story 1878475) (#1289)

* Add article, redirects, toc * Update dotnet-desktop-guide/net/wpf/events/how-to-create-a-custom-routed-event.md Co-authored-by: Andy (Steve) De George <[email protected]> * Update dotnet-desktop-guide/net/wpf/events/snippets/how-to-create-a-custom-routed-event/csharp/CodeSample.csproj Co-authored-by: Andy (Steve) De George <[email protected]> * Update dotnet-desktop-guide/net/wpf/events/snippets/how-to-create-a-custom-routed-event/vb/CodeSampleVb.vbproj Co-authored-by: Andy (Steve) De George <[email protected]> * Update dotnet-desktop-guide/net/wpf/events/snippets/how-to-create-a-custom-routed-event/WpfControlLibraryCsharp/WpfControlLibrary.csproj Co-authored-by: Andy (Steve) De George <[email protected]> * Use local project references Co-authored-by: Andy (Steve) De George <[email protected]>
2026-09-08 23:43:29 +02:00 · 2022-02-10 14:49:46 -08:00
parent 9750f50961
commit 51977cea61
24 changed files with 622 additions and 0 deletions
@@ -0,0 +1,45 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+
+namespace WpfControl
+{
+    //<CustomButton>
+    public class CustomButton : Button
+    {
+        // Register a custom routed event using the Bubble routing strategy.
+        public static readonly RoutedEvent ConditionalClickEvent = EventManager.RegisterRoutedEvent(
+            name: "ConditionalClick",
+            routingStrategy: RoutingStrategy.Bubble,
+            handlerType: typeof(RoutedEventHandler),
+            ownerType: typeof(CustomButton));
+
+        // Provide CLR accessors for assigning an event handler.
+        public event RoutedEventHandler ConditionalClick
+        {
+            add { AddHandler(ConditionalClickEvent, value); }
+            remove { RemoveHandler(ConditionalClickEvent, value); }
+        }
+
+        void RaiseCustomRoutedEvent()
+        {
+            // Create a RoutedEventArgs instance.
+            RoutedEventArgs routedEventArgs = new(routedEvent: ConditionalClickEvent);
+
+            // Raise the event, which will bubble up through the element tree.
+            RaiseEvent(routedEventArgs);
+        }
+
+        // For demo purposes, we use the Click event as a trigger.
+        protected override void OnClick()
+        {
+            // Some condition combined with the Click event will trigger the ConditionalClick event.
+            if (DateTime.Now > new DateTime())
+                RaiseCustomRoutedEvent();
+
+            // Call the base class OnClick() method so Click event subscribers are notified.
+            base.OnClick();
+        }
+    }
+    //</CustomButton>
+}
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+</Project>
@@ -0,0 +1,53 @@
+Imports System.Windows
+Imports System.Windows.Controls
+
+'<CustomButton>
+Public Class CustomButton
+    Inherits Button
+
+    ' Register a custom routed event with the Bubble routing strategy.
+    Public Shared ReadOnly ConditionalClickEvent As RoutedEvent = EventManager.RegisterRoutedEvent(
+        name:="ConditionalClick",
+        routingStrategy:=RoutingStrategy.Bubble,
+        handlerType:=GetType(RoutedEventHandler),
+        ownerType:=GetType(CustomButton))
+
+    ' Provide CLR accessors to support event handler assignment.
+    Public Custom Event ConditionalClick As RoutedEventHandler
+
+        AddHandler(value As RoutedEventHandler)
+            [AddHandler](ConditionalClickEvent, value)
+        End AddHandler
+
+        RemoveHandler(value As RoutedEventHandler)
+            [RemoveHandler](ConditionalClickEvent, value)
+        End RemoveHandler
+
+        RaiseEvent(sender As Object, e As RoutedEventArgs)
+            [RaiseEvent](e)
+        End RaiseEvent
+
+    End Event
+
+    Private Sub RaiseCustomRoutedEvent()
+
+        ' Create a RoutedEventArgs instance.
+        Dim routedEventArgs As New RoutedEventArgs(routedEvent:=ConditionalClickEvent)
+
+        ' Raise the event, which will bubble up through the element tree.
+        [RaiseEvent](routedEventArgs)
+
+    End Sub
+
+    ' For demo purposes, we use the Click event as a trigger.
+    Protected Overrides Sub OnClick()
+
+        ' Some condition combined with the Click event will trigger the ConditionalClick event.
+        If Date.Now > New DateTime() Then RaiseCustomRoutedEvent()
+
+        ' Call the base class OnClick() method so Click event subscribers are notified.
+        MyBase.OnClick()
+
+    End Sub
+End Class
+'</CustomButton>
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>WpfControlVb</RootNamespace>
+    <AssemblyName>WpfControlLibraryVb</AssemblyName>
+    <TargetFramework>net6.0-windows</TargetFramework>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+</Project>
@@ -0,0 +1,11 @@
+using System.Windows;
+
+namespace CodeSample
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App : Application
+    {
+    }
+}
@@ -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)
+)]
@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net6.0-windows</TargetFramework>
+    <UseWPF>true</UseWPF>
+    <NeutralLanguage>en-us</NeutralLanguage>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\WpfControlLibraryCsharp\WpfControlLibrary.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="Properties\Resources.Designer.cs">
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
+      <DependentUpon>Resources.resx</DependentUpon>
+    </Compile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <EmbeddedResource Update="Properties\Resources.resx">
+      <Generator>ResXFileCodeGenerator</Generator>
+      <LastGenOutput>Resources.Designer.cs</LastGenOutput>
+    </EmbeddedResource>
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,17 @@
+<!--<MainWindowXaml>-->
+<Window x:Class="CodeSample.MainWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:custom="clr-namespace:WpfControl;assembly=WpfControlLibrary"
+        Title="How to create a custom routed event" Height="100" Width="300">
+
+    <StackPanel Name="StackPanel1" custom:CustomButton.ConditionalClick="Handler_ConditionalClick">
+        <custom:CustomButton
+            Name="customButton"
+            ConditionalClick="Handler_ConditionalClick"
+            Content="Click to trigger a custom routed event"
+            Background="LightGray">
+        </custom:CustomButton>
+    </StackPanel>
+</Window>
+<!--</MainWindowXaml>-->
@@ -0,0 +1,42 @@
+using System.Diagnostics;
+using System.Windows;
+
+namespace CodeSample
+{
+    public partial class MainWindow : Window
+    {
+        public MainWindow()
+        {
+            InitializeComponent();
+
+            // Assign an event handler to the CustomButton using the '+=' operator.
+            // customButton.ConditionalClick += Handler_ConditionalClick;
+
+            // Assign an event handler to the CustomButton using the AddHandler method.
+            // customButton.AddHandler(WpfControl.CustomButton.ConditionalClickEvent,
+            //   new RoutedEventHandler(Handler_ConditionalClick));
+
+            // Assign an event handler to the StackPanel using the AddHandler method.
+            // StackPanel1.AddHandler(WpfControl.CustomButton.ConditionalClickEvent, 
+            //   new RoutedEventHandler(Handler_ConditionalClick));
+        }
+
+        //<EventHandler>
+        // The ConditionalClick event handler.
+        private void Handler_ConditionalClick(object sender, RoutedEventArgs e)
+        {
+            string senderName = ((FrameworkElement)sender).Name;
+            string sourceName = ((FrameworkElement)e.Source).Name;
+
+            Debug.WriteLine($"Routed event handler attached to {senderName}, " +
+                $"triggered by the ConditionalClick routed event raised on {sourceName}.");
+        }
+
+        // Debug output when CustomButton is clicked:
+        // Routed event handler attached to CustomButton,
+        //     triggered by the ConditionalClick routed event raised on CustomButton.
+        // Routed event handler attached to StackPanel1,
+        //     triggered by the ConditionalClick routed event raised on CustomButton.
+        //</EventHandler>
+    }
+}
@@ -0,0 +1,63 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     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.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+namespace CodeSample.Properties {
+    using System;
+    
+    
+    /// <summary>
+    ///   A strongly-typed resource class, for looking up localized strings, etc.
+    /// </summary>
+    // 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", "17.0.0.0")]
+    [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() {
+        }
+        
+        /// <summary>
+        ///   Returns the cached ResourceManager instance used by this class.
+        /// </summary>
+        [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("CodeSample.Properties.Resources", typeof(Resources).Assembly);
+                    resourceMan = temp;
+                }
+                return resourceMan;
+            }
+        }
+        
+        /// <summary>
+        ///   Overrides the current thread's CurrentUICulture property for all
+        ///   resource lookups using this strongly typed resource class.
+        /// </summary>
+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
+        internal static global::System.Globalization.CultureInfo Culture {
+            get {
+                return resourceCulture;
+            }
+            set {
+                resourceCulture = value;
+            }
+        }
+    }
+}
@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>
@@ -0,0 +1,9 @@
+<Application x:Class="CodeSample.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:CodeSample"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+         
+    </Application.Resources>
+</Application>
@@ -0,0 +1,9 @@
+<Application x:Class="Application"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:CodeSampleVb"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+         
+    </Application.Resources>
+</Application>
@@ -0,0 +1,6 @@
+Class Application
+
+    ' Application-level events, such as Startup, Exit, and DispatcherUnhandledException
+    ' can be handled in this file.
+
+End Class
@@ -0,0 +1,9 @@
+'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)
+<Assembly: ThemeInfo(ResourceDictionaryLocation.None, ResourceDictionaryLocation.SourceAssembly)>
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net6.0-windows</TargetFramework>
+    <RootNamespace>CodeSampleVb</RootNamespace>
+    <NeutralLanguage>en-us</NeutralLanguage>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Import Include="System.Windows" />
+    <Import Include="System.Windows.Controls" />
+    <Import Include="System.Windows.Data" />
+    <Import Include="System.Windows.Documents" />
+    <Import Include="System.Windows.Input" />
+    <Import Include="System.Windows.Media" />
+    <Import Include="System.Windows.Media.Imaging" />
+    <Import Include="System.Windows.Navigation" />
+    <Import Include="System.Windows.Shapes" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\WpfControlLibraryVb\WpfControlLibraryVb.vbproj" />
+  </ItemGroup>
+
+</Project>
@@ -0,0 +1,17 @@
+<!--<MainWindowXaml>-->
+<Window x:Class="CodeSampleVb.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:custom="clr-namespace:WpfControlVb;assembly=WpfControlLibraryVb"
+        Title="How to create a custom routed event" Height="100" Width="300">
+
+    <StackPanel Name="StackPanel1">
+        <custom:CustomButton
+            Name="customButton"
+            ConditionalClick="Handler_ConditionalClick"
+            Content="Click to trigger a custom routed event"
+            Background="LightGray">
+        </custom:CustomButton>
+    </StackPanel>
+</Window>
+<!--</MainWindowXaml>-->
@@ -0,0 +1,39 @@
+Namespace CodeSampleVb
+    Partial Public Class MainWindow
+        Inherits Window
+
+        Public Sub New()
+            InitializeComponent()
+
+            ' Assign an event handler to CustomButton using the AddHandler statement.
+            '   AddHandler customButton.ConditionalClick, AddressOf Handler_ConditionalClick
+
+            ' Assign an event handler to CustomButton using the AddHandler method.
+            ' customButton.[AddHandler](WpfControlVb.CustomButton.ConditionalClickEvent,
+            '   New RoutedEventHandler(AddressOf Handler_ConditionalClick))
+
+            ' Assign an event handler to StackPanel1 using the AddHandler method.
+            ' StackPanel1.[AddHandler](WpfControlVb.CustomButton.ConditionalClickEvent,
+            '   New RoutedEventHandler(AddressOf Handler_ConditionalClick))
+        End Sub
+
+        '<EventHandler>
+        ' The ConditionalClick event handler.
+        Private Sub Handler_ConditionalClick(sender As Object, e As RoutedEventArgs)
+
+            Dim sourceName As String = CType(e.Source, FrameworkElement).Name
+            Dim senderName As String = CType(sender, FrameworkElement).Name
+
+            Debug.WriteLine($"Routed event handler attached to {senderName}, " +
+                $"triggered by the ConditionalClick routed event raised on {sourceName}.")
+
+        End Sub
+
+        ' Debug output when CustomButton is clicked:
+        ' Routed event handler attached to CustomButton,
+        '     triggered by the ConditionalClick routed event raised on CustomButton.
+        ' Routed event handler attached to StackPanel1,
+        '     triggered by the ConditionalClick routed event raised on CustomButton.
+        '</EventHandler>
+    End Class
+End Namespace