Content update - Dependency properties collection (user story 1878471) (#1173)

* Add code snippets * Add article and updated code snippets * Resolve conflicts * Make reviewer requested changes * Name class parameters and show how to pass in default value in metedata * Add example for creating a FreezableCollection type dependency property * Add newline * Further edits
2026-09-07 16:06:07 +02:00 · 2021-10-22 09:55:35 -07:00
parent 090e480dcf
commit cf712b82b0
18 changed files with 695 additions and 0 deletions
@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Data;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace CodeSampleCsharp
+{
+    /// <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 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net5.0-windows</TargetFramework>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+  <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 +1,11 @@
+<Window x:Class="CodeSampleCsharp.MainWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:src="clr-namespace:CodeSampleCsharp"
+        Title="Collection-Type Dependency Properties" Height="100" Width="400">
+
+    <StackPanel>
+
+        <Button Click="InitializeAquariums">Set collection default value in class constructor</Button>
+
+    </StackPanel>
+</Window>
@@ -0,0 +1,141 @@
+using System.Collections.Generic;
+using System.Windows;
+
+namespace CodeSampleCsharp
+{
+    /// <summary>
+    /// Interaction logic for MainWindow.xaml.
+    /// </summary>
+    public partial class MainWindow : Window
+    {
+        //<InitializeAquariums>
+        private void InitializeAquariums(object sender, RoutedEventArgs e)
+        {
+            Aquarium aquarium1 = new();
+            Aquarium aquarium2 = new();
+            aquarium1.AquariumContents.Add(new Fish());
+            aquarium2.AquariumContents.Add(new Fish());
+            MessageBox.Show(
+                $"Aquarium1 contains {aquarium1.AquariumContents.Count} fish\r\n" +
+                $"Aquarium2 contains {aquarium2.AquariumContents.Count} fish");
+        }
+        //</InitializeAquariums>
+    }
+
+    //<SetCollectionDefaultValueInConstructor>
+    public class Aquarium : DependencyObject
+    {
+        // Register a dependency property with the specified property name,
+        // property type, owner type, and property metadata.
+        private static readonly DependencyPropertyKey s_aquariumContentsPropertyKey =
+            DependencyProperty.RegisterReadOnly(
+              name: "AquariumContents",
+              propertyType: typeof(List<FrameworkElement>),
+              ownerType: typeof(Aquarium),
+              typeMetadata: new FrameworkPropertyMetadata()
+              //typeMetadata: new FrameworkPropertyMetadata(new List<FrameworkElement>())
+            );
+
+        // Store the dependency property identifier as a static member of the class.
+        public static readonly DependencyProperty AquariumContentsProperty =
+            s_aquariumContentsPropertyKey.DependencyProperty;
+
+        // Set the default collection value in a class constructor.
+        public Aquarium() => SetValue(s_aquariumContentsPropertyKey, new List<FrameworkElement>());
+
+        // Declare a read-only property.
+        public List<FrameworkElement> AquariumContents =>
+            (List<FrameworkElement>)GetValue(AquariumContentsProperty);
+    }
+
+    public class Fish : FrameworkElement { }
+    //</SetCollectionDefaultValueInConstructor>
+
+    public class ReadWriteAquariumContents
+    {
+        private static void InitializeAquariums()
+        {
+            Aquarium aquarium1 = new();
+            Aquarium aquarium2 = new();
+            aquarium1.AquariumContents.Add(new Fish());
+            aquarium2.AquariumContents.Add(new Fish());
+            aquarium2.AquariumContents = new List<FrameworkElement>();
+            MessageBox.Show(
+                $"Aquarium1 contains {aquarium1.AquariumContents.Count} fish\r\n" +
+                $"Aquarium2 contains {aquarium2.AquariumContents.Count} fish");
+        }
+
+        //<ReadWriteDependencyProperty>
+        public class Aquarium : DependencyObject
+        {
+            // Register a dependency property with the specified property name,
+            // property type, and owner type.
+            private static readonly DependencyProperty s_aquariumContentsProperty =
+                DependencyProperty.Register(
+                  name: "AquariumContents",
+                  propertyType: typeof(List<FrameworkElement>),
+                  ownerType: typeof(Aquarium)
+                );
+
+            // Store the dependency property identifier as a static member of the class.
+            public static readonly DependencyProperty AquariumContentsProperty =
+                s_aquariumContentsProperty;
+
+            // Set the default collection value in a class constructor.
+            public Aquarium() => SetValue(s_aquariumContentsProperty, new List<FrameworkElement>());
+
+            // Declare a read-write property.
+            public List<FrameworkElement> AquariumContents
+            {
+                get => (List<FrameworkElement>)GetValue(AquariumContentsProperty);
+                set => SetValue(AquariumContentsProperty, value);
+            }
+        }
+        //</ReadWriteDependencyProperty>
+
+        public class Fish : FrameworkElement { }
+    }
+
+    public class FreezableCollectionAquarium
+    {
+        public static void InitializeAquariums()
+        {
+            Aquarium aquarium1 = new();
+            Aquarium aquarium2 = new();
+            aquarium1.AquariumContents.Add(new Fish());
+            aquarium2.AquariumContents.Add(new Fish());
+            MessageBox.Show(
+                $"Aquarium1 contains {aquarium1.AquariumContents.Count} fish\r\n" +
+                $"Aquarium2 contains {aquarium2.AquariumContents.Count} fish");
+        }
+
+        //<FreezableCollectionAquarium>
+        public class Aquarium : DependencyObject
+        {
+            // Register a dependency property with the specified property name,
+            // property type, and owner type.
+            private static readonly DependencyPropertyKey s_aquariumContentsPropertyKey =
+                DependencyProperty.RegisterReadOnly(
+                  name: "AquariumContents",
+                  propertyType: typeof(FreezableCollection<FrameworkElement>),
+                  ownerType: typeof(Aquarium),
+                  typeMetadata: new FrameworkPropertyMetadata()
+                );
+
+            // Store the dependency property identifier as a static member of the class.
+            public static readonly DependencyProperty AquariumContentsProperty =
+                s_aquariumContentsPropertyKey.DependencyProperty;
+
+            // Set the default collection value in a class constructor.
+            public Aquarium() => SetValue(s_aquariumContentsPropertyKey, new FreezableCollection<FrameworkElement>());
+
+            // Declare a read-only property.
+            public FreezableCollection<FrameworkElement> AquariumContents =>
+                (FreezableCollection<FrameworkElement>)GetValue(AquariumContentsProperty);
+        }
+
+        //</FreezableCollectionAquarium>
+
+        public class Fish : FrameworkElement { }
+    }
+}
@@ -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 CodeSampleCsharp.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", "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() {
+        }
+        
+        /// <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("CodeSampleCsharp.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="CodeSampleCsharp.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:CodeSampleCsharp"
+             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 +1,11 @@
+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)
+<Assembly: ThemeInfo(ResourceDictionaryLocation.None, ResourceDictionaryLocation.SourceAssembly)>
@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net5.0-windows</TargetFramework>
+    <RootNamespace>CodeSampleVb</RootNamespace>
+    <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>
+
+</Project>
@@ -0,0 +1,11 @@
+<Window x:Class="CodeSampleVb.MainWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:src="clr-namespace:CodeSampleCsharp"
+        Title="Collection-Type Dependency Properties" Height="100" Width="400">
+
+    <StackPanel>
+
+        <Button Click="InitializeAquariums">Set collection default value in class constructor</Button>
+
+    </StackPanel>
+</Window>
@@ -0,0 +1,161 @@
+Namespace CodeSampleVb
+
+    ' <summary>
+    ' Interaction logic for MainWindow.xaml.
+    ' </summary>
+    Partial Public Class MainWindow
+        Inherits Window
+
+        Public Sub New()
+            InitializeComponent()
+        End Sub
+
+        '<InitializeAquariums>
+        Private Sub InitializeAquariums(sender As Object, e As RoutedEventArgs)
+            Dim aquarium1 As New Aquarium()
+            Dim aquarium2 As New Aquarium()
+            aquarium1.AquariumContents.Add(New Fish())
+            aquarium2.AquariumContents.Add(New Fish())
+            MessageBox.Show($"Aquarium1 contains {aquarium1.AquariumContents.Count} fish{Environment.NewLine}" +
+                            $"Aquarium2 contains {aquarium2.AquariumContents.Count} fish")
+        End Sub
+        '</InitializeAquariums>
+
+    End Class
+
+    '<SetCollectionDefaultValueInConstructor>
+    Public Class Aquarium
+        Inherits DependencyObject
+
+        ' Register a dependency property with the specified property name,
+        ' property type, owner type, and property metadata.
+        Private Shared ReadOnly s_aquariumContentsPropertyKey As DependencyPropertyKey =
+            DependencyProperty.RegisterReadOnly(
+                name:="AquariumContents",
+                propertyType:=GetType(List(Of FrameworkElement)),
+                ownerType:=GetType(Aquarium),
+                typeMetadata:=New FrameworkPropertyMetadata())
+                'typeMetadata:=New FrameworkPropertyMetadata(New List(Of FrameworkElement)))
+
+        ' Store the dependency property identifier as a static member of the class.
+        Public Shared ReadOnly AquariumContentsProperty As DependencyProperty =
+            s_aquariumContentsPropertyKey.DependencyProperty
+
+        ' Set the default collection value in a class constructor.
+        Public Sub New()
+            SetValue(s_aquariumContentsPropertyKey, New List(Of FrameworkElement)())
+        End Sub
+
+        ' Declare a read-only property.
+        Public ReadOnly Property AquariumContents As List(Of FrameworkElement)
+            Get
+                Return CType(GetValue(AquariumContentsProperty), List(Of FrameworkElement))
+            End Get
+        End Property
+    End Class
+
+    Public Class Fish
+        Inherits FrameworkElement
+    End Class
+    '</SetCollectionDefaultValueInConstructor>
+
+    Public Class ReadWriteAquariumContents
+
+        Public Shared Sub InitializeAquariums()
+            Dim aquarium1 As New Aquarium()
+            Dim aquarium2 As New Aquarium()
+            aquarium1.AquariumContents.Add(New Fish())
+            aquarium2.AquariumContents.Add(New Fish())
+            aquarium2.AquariumContents = New List(Of FrameworkElement)()
+            MessageBox.Show($"Aquarium1 contains {aquarium1.AquariumContents.Count} fish{Environment.NewLine}" +
+                            $"Aquarium2 contains {aquarium2.AquariumContents.Count} fish")
+        End Sub
+
+        '<ReadWriteDependencyProperty>
+        Public Class Aquarium
+            Inherits DependencyObject
+
+            ' Register a dependency property with the specified property name,
+            ' property type, and owner type.
+            Private Shared ReadOnly s_aquariumContentsProperty As DependencyProperty =
+                DependencyProperty.Register(
+                    name:="AquariumContents",
+                    propertyType:=GetType(List(Of FrameworkElement)),
+                    ownerType:=GetType(Aquarium))
+
+            ' Store the dependency property identifier as a static member of the class.
+            Public Shared ReadOnly AquariumContentsProperty As DependencyProperty =
+                s_aquariumContentsProperty
+
+            ' Set the default collection value in a class constructor.
+            Public Sub New()
+                SetValue(s_aquariumContentsProperty, New List(Of FrameworkElement)())
+            End Sub
+
+            ' Declare a read-write property.
+            Public Property AquariumContents As List(Of FrameworkElement)
+                Get
+                    Return CType(GetValue(AquariumContentsProperty), List(Of FrameworkElement))
+                End Get
+                Set
+                    SetValue(AquariumContentsProperty, Value)
+                End Set
+            End Property
+        End Class
+        '</ReadWriteDependencyProperty>
+
+        Public Class Fish
+            Inherits FrameworkElement
+        End Class
+
+    End Class
+
+    Public Class FreezableCollectionAquarium
+
+        Public Shared Sub InitializeAquariums()
+            Dim aquarium1 As New Aquarium()
+            Dim aquarium2 As New Aquarium()
+            aquarium1.AquariumContents.Add(New Fish())
+            aquarium2.AquariumContents.Add(New Fish())
+            MessageBox.Show($"Aquarium1 contains {aquarium1.AquariumContents.Count} fish{Environment.NewLine}" +
+                            $"Aquarium2 contains {aquarium2.AquariumContents.Count} fish")
+        End Sub
+
+        '<FreezableCollectionAquarium>
+        Public Class Aquarium
+            Inherits DependencyObject
+
+            ' Register a dependency property with the specified property name,
+            ' property type, and owner type.
+            Private Shared ReadOnly s_aquariumContentsPropertyKey As DependencyPropertyKey =
+                DependencyProperty.RegisterReadOnly(
+                    name:="AquariumContents",
+                    propertyType:=GetType(FreezableCollection(Of FrameworkElement)),
+                    ownerType:=GetType(Aquarium),
+                    typeMetadata:=New FrameworkPropertyMetadata())
+
+            ' Store the dependency property identifier as a static member of the class.
+            Public Shared ReadOnly AquariumContentsProperty As DependencyProperty =
+                s_aquariumContentsPropertyKey.DependencyProperty
+
+            ' Set the default collection value in a class constructor.
+            Public Sub New()
+                SetValue(s_aquariumContentsPropertyKey, New FreezableCollection(Of FrameworkElement)())
+            End Sub
+
+            ' Declare a read-only property.
+            Public ReadOnly Property AquariumContents As FreezableCollection(Of FrameworkElement)
+                Get
+                    Return CType(GetValue(AquariumContentsProperty), FreezableCollection(Of FrameworkElement))
+                End Get
+            End Property
+        End Class
+        '</FreezableCollectionAquarium>
+
+        Public Class Fish
+            Inherits FrameworkElement
+        End Class
+
+    End Class
+
+End Namespace