逐步解說：使用 ElementHost 控制項對應屬性

發行項
08/12/2011

本逐步解說顯示如何使用 PropertyMap 屬性將 Windows Forms 屬性對應至裝載之 WPF 項目上的對應屬性。

逐步解說將說明的工作包括：

建立專案。
定義新的屬性對應。
移除預設的屬性對應。
擴充預設的屬性對應。

如需這個逐步解說中所說明之工作的完整程式碼清單，請參閱使用 ElementHost 控制項對應屬性範例 (英文)。

完成時，就可以將 Windows Forms 屬性對應至裝載之項目上的對應 WPF 屬性。

必要條件

您需要下列元件才能完成此逐步解說：

Visual Studio 2008。

建立專案

若要建立專案

建立 Windows Forms 應用程式專案，取名為 PropertyMappingWithElementHost。如需詳細資訊，請參閱 HOW TO：建立新的 Windows Form 應用程式專案。
在 [方案總管] 中加入下列 WPF 組件的參考。
- PresentationCore
- PresentationFramework
- WindowsBase
- WindowsFormsIntegration

將下列程式碼複製至 Form1 程式碼檔案的最上面。

Imports System.Windows
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Forms.Integration

using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Forms.Integration;

在 Windows Form 設計工具中開啟表單 Form1。按兩下表單加入 Load 事件的事件處理常式。
回到 [Windows Form 設計工具]，並加入表單的 Resize 事件的事件處理常式。如需詳細資訊，請參閱 HOW TO：使用設計工具建立事件處理常式。

在 Form1 類別中宣告 ElementHost 欄位。

Private elemHost As ElementHost = Nothing

ElementHost elemHost = null;

定義新的屬性對應

ElementHost 控制項會提供數個預設的屬性對應。您可以藉由在 ElementHost 控制項的 PropertyMap 上呼叫 Add 方法，加入新的屬性對應。

若要定義新的屬性對應

將下列程式碼複製到 Form1 類別的定義中。

' The AddMarginMapping method adds a new property mapping
' for the Margin property.
Private Sub AddMarginMapping()

    elemHost.PropertyMap.Add( _
        "Margin", _
        New PropertyTranslator(AddressOf OnMarginChange))

End Sub


' The OnMarginChange method implements the mapping 
' from the Windows Forms Margin property to the
' Windows Presentation Foundation Margin property.
'
' The provided Padding value is used to construct 
' a Thickness value for the hosted element's Margin
' property.
Private Sub OnMarginChange( _
ByVal h As Object, _
ByVal propertyName As String, _
ByVal value As Object)

    Dim host As ElementHost = h
    Dim p As Padding = CType(value, Padding)
    Dim wpfButton As System.Windows.Controls.Button = host.Child


    Dim t As New Thickness(p.Left, p.Top, p.Right, p.Bottom)

    wpfButton.Margin = t

End Sub

// The AddMarginMapping method adds a new property mapping
// for the Margin property.
private void AddMarginMapping()
{
    elemHost.PropertyMap.Add(
        "Margin",
        new PropertyTranslator(OnMarginChange));
}

// The OnMarginChange method implements the mapping 
// from the Windows Forms Margin property to the
// Windows Presentation Foundation Margin property.
//
// The provided Padding value is used to construct 
// a Thickness value for the hosted element's Margin
// property.
private void OnMarginChange(object h, String propertyName, object value)
{
    ElementHost host = h as ElementHost;
    Padding p = (Padding)value;
    System.Windows.Controls.Button wpfButton = 
        host.Child as System.Windows.Controls.Button;

    Thickness t = new Thickness(p.Left, p.Top, p.Right, p.Bottom );

    wpfButton.Margin = t;
}

AddMarginMapping 方法會加入 Margin 屬性的新對應。

OnMarginChange 方法會將 Margin 屬性轉譯成 WPF Margin 屬性。

將下列程式碼複製到 Form1 類別的定義中。

' The AddRegionMapping method assigns a custom 
' mapping for the Region property.
Private Sub AddRegionMapping()

    elemHost.PropertyMap.Add( _
        "Region", _
        New PropertyTranslator(AddressOf OnRegionChange))

End Sub


' The OnRegionChange method assigns an EllipseGeometry to
' the hosted element's Clip property.
Private Sub OnRegionChange( _
ByVal h As Object, _
ByVal propertyName As String, _
ByVal value As Object)

    Dim host As ElementHost = h

    Dim wpfButton As System.Windows.Controls.Button = host.Child

    wpfButton.Clip = New EllipseGeometry(New Rect( _
        0, _
        0, _
        wpfButton.ActualWidth, _
        wpfButton.ActualHeight))

End Sub


' The Form1_Resize method handles the form's Resize event.
' It calls the OnRegionChange method explicitly to 
' assign a new clipping geometry to the hosted element.
Private Sub Form1_Resize( _
ByVal sender As Object, _
ByVal e As EventArgs) Handles MyBase.Resize

    If elemHost IsNot Nothing Then
        Me.OnRegionChange(elemHost, "Region", Nothing)
    End If

End Sub

// The AddRegionMapping method assigns a custom 
// mapping for the Region property.
private void AddRegionMapping()
{
    elemHost.PropertyMap.Add(
        "Region",
        new PropertyTranslator(OnRegionChange));
}

// The OnRegionChange method assigns an EllipseGeometry to
// the hosted element's Clip property.
private void OnRegionChange(
    object h, 
    String propertyName, 
    object value)
{
    ElementHost host = h as ElementHost;
    System.Windows.Controls.Button wpfButton = 
        host.Child as System.Windows.Controls.Button;

    wpfButton.Clip = new EllipseGeometry(new Rect(
        0, 
        0, 
        wpfButton.ActualWidth, 
        wpfButton.ActualHeight));
}

// The Form1_Resize method handles the form's Resize event.
// It calls the OnRegionChange method explicitly to 
// assign a new clipping geometry to the hosted element.
private void Form1_Resize(object sender, EventArgs e)
{
    this.OnRegionChange(elemHost, "Region", null);
}

AddRegionMapping 方法會加入 Region 屬性的新對應。

OnRegionChange 方法會將 Region 屬性轉譯成 WPF Clip 屬性。

Form1_Resize 方法會處理表單的 Resize 事件，並且調整裁剪區域的大小以符合裝載的項目。

移除預設的屬性對應

您可以藉由在 ElementHost 控制項的 PropertyMap 上呼叫 Remove 方法，移除預設的屬性對應。

若要移除預設的屬性對應

將下列程式碼複製到 Form1 類別的定義中。

' The RemoveCursorMapping method deletes the default
' mapping for the Cursor property.
Private Sub RemoveCursorMapping()
    elemHost.PropertyMap.Remove("Cursor")
End Sub

// The RemoveCursorMapping method deletes the default
// mapping for the Cursor property.
private void RemoveCursorMapping()
{
    elemHost.PropertyMap.Remove("Cursor");
}

RemoveCursorMapping 方法會刪除 Cursor 屬性的預設對應。

擴充預設的屬性對應

您可以使用預設的屬性對應，同時以自己的對應加以擴充。

若要擴充預設的屬性對應

將下列程式碼複製到 Form1 類別的定義中。

' The ExtendBackColorMapping method adds a property
' translator if a mapping already exists.
Private Sub ExtendBackColorMapping()

    If elemHost.PropertyMap("BackColor") IsNot Nothing Then

        elemHost.PropertyMap("BackColor") = PropertyTranslator.Combine( _
            elemHost.PropertyMap("BackColor"), _
            PropertyTranslator.CreateDelegate( _
            GetType(PropertyTranslator), _
            Me, _
            "OnBackColorChange"))
    End If

End Sub


' The OnBackColorChange method assigns a specific image 
' to the hosted element's Background property.
Private Sub OnBackColorChange( _
ByVal h As Object, _
ByVal propertyName As String, _
ByVal value As Object)

    Dim host As ElementHost = h
    Dim wpfButton As System.Windows.Controls.Button = host.Child
    Dim b As New ImageBrush(New BitmapImage( _
        New Uri("file:///C:\WINDOWS\Santa Fe Stucco.bmp")))
    wpfButton.Background = b

End Sub

// The ExtendBackColorMapping method adds a property
// translator if a mapping already exists.
private void ExtendBackColorMapping()
{
    if (elemHost.PropertyMap["BackColor"] != null)
    {
        elemHost.PropertyMap["BackColor"] += 
            new PropertyTranslator(OnBackColorChange);
    }
}

// The OnBackColorChange method assigns a specific image 
// to the hosted element's Background property.
private void OnBackColorChange(object h, String propertyName, object value)
{
    ElementHost host = h as ElementHost;
    System.Windows.Controls.Button wpfButton = 
        host.Child as System.Windows.Controls.Button;

    ImageBrush b = new ImageBrush(new BitmapImage(
        new Uri(@"file:///C:\WINDOWS\Santa Fe Stucco.bmp")));
    wpfButton.Background = b;
}

ExtendBackColorMapping 方法會將自訂屬性轉譯器加入至現有的 BackColor 屬性對應。

OnBackColorChange 方法會將特定的影像指派至裝載之控制項的 Background 屬性。套用預設屬性對應之後，就會呼叫 OnBackColorChange 方法。

初始化屬性對應

若要初始化屬性對應

將下列程式碼複製到 Form1 類別的定義中。

Private Sub Form1_Load( _
ByVal sender As Object, _
ByVal e As EventArgs) Handles MyBase.Load

    ' Create the ElementHost control.
    elemHost = New ElementHost()
    elemHost.Dock = DockStyle.Fill
    Me.Controls.Add(elemHost)

    ' Create a Windows Presentation Foundation Button element 
    ' and assign it as the ElementHost control's child. 
    Dim wpfButton As New System.Windows.Controls.Button()
    wpfButton.Content = "Windows Presentation Foundation Button"
    elemHost.Child = wpfButton

    ' Map the Margin property.
    Me.AddMarginMapping()

    ' Remove the mapping for the Cursor property.
    Me.RemoveCursorMapping()

    ' Add a mapping for the Region property.
    Me.AddRegionMapping()

    ' Add another mapping for the BackColor property.
    Me.ExtendBackColorMapping()

    ' Cause the OnMarginChange delegate to be called.
    elemHost.Margin = New Padding(23, 23, 23, 23)

    ' Cause the OnRegionChange delegate to be called.
    elemHost.Region = New [Region]()

    ' Cause the OnBackColorChange delegate to be called.
    elemHost.BackColor = System.Drawing.Color.AliceBlue

End Sub

private void Form1_Load(object sender, EventArgs e)
{
    // Create the ElementHost control.
    elemHost = new ElementHost();
    elemHost.Dock = DockStyle.Fill;
    this.Controls.Add(elemHost);

    // Create a Windows Presentation Foundation Button element 
    // and assign it as the ElementHost control's child. 
    System.Windows.Controls.Button wpfButton = new System.Windows.Controls.Button();
    wpfButton.Content = "Windows Presentation Foundation Button";
    elemHost.Child = wpfButton;

    // Map the Margin property.
    this.AddMarginMapping();

    // Remove the mapping for the Cursor property.
    this.RemoveCursorMapping();

    // Add a mapping for the Region property.
    this.AddRegionMapping();

    // Add another mapping for the BackColor property.
    this.ExtendBackColorMapping();

    // Cause the OnMarginChange delegate to be called.
    elemHost.Margin = new Padding(23, 23, 23, 23);

    // Cause the OnRegionChange delegate to be called.
    elemHost.Region = new Region();

    // Cause the OnBackColorChange delegate to be called.
    elemHost.BackColor = System.Drawing.Color.AliceBlue;
}

Form1_Load 方法會處理 Load 事件並執行下列初始化。

建立 WPF Button 項目。
呼叫您稍早在這個逐步解說中定義的方法，以設定屬性對應。
將初始值指派給對應的屬性。

按 F5 建置並執行應用程式。

請參閱

共用方式為

逐步解說：使用 ElementHost 控制項對應屬性

必要條件

建立專案

若要建立專案

定義新的屬性對應

若要定義新的屬性對應

移除預設的屬性對應

若要移除預設的屬性對應

擴充預設的屬性對應

若要擴充預設的屬性對應

初始化屬性對應

若要初始化屬性對應

請參閱

參考

概念

其他資源

其他資源