公开服务器端 UI 自动化提供程序
更新：2007 年 11 月
本主题包含示例代码，该示例代码演示如何公开 System.Windows.Forms.Control 窗口中承载的服务器端 UI 自动化提供程序。
示例重写窗口过程以捕获 WM_GETOBJECT，这是在客户端应用程序请求有关该窗口的信息时由 UI 自动化核心服务发送的消息。
示例
''' <summary>
''' Handles WM_GETOBJECT message; others are passed to base handler.
''' </summary>
''' <param name="m">Windows message.</param>
''' <remarks>
''' This method enables UI Automation to find the control.
''' In this example, the implementation of IRawElementProvider is in the same class
''' as this method.
''' </remarks>
Protected Overrides Sub WndProc(ByRef m As Message)
Const WM_GETOBJECT As Integer = &H3D
If m.Msg = WM_GETOBJECT AndAlso m.LParam.ToInt32() = AutomationInteropProvider.RootObjectId Then
m.Result = AutomationInteropProvider.ReturnRawElementProvider(Me.Handle, m.WParam, m.LParam, DirectCast(Me, IRawElementProviderSimple))
Return
End If
MyBase.WndProc(m)
End Sub 'WndProc
/// <summary>
/// Handles WM_GETOBJECT message; others are passed to base handler.
/// </summary>
/// <param name="m">Windows message.</param>
/// <remarks>
/// This method enables UI Automation to find the control.
/// In this example, the implementation of IRawElementProvider is in the same class
/// as this method.
/// </remarks>
protected override void WndProc(ref Message m)
{
const int WM_GETOBJECT = 0x003D;
if ((m.Msg == WM_GETOBJECT) && (m.LParam.ToInt32() ==
AutomationInteropProvider.RootObjectId))
{
m.Result = AutomationInteropProvider.ReturnRawElementProvider(
this.Handle, m.WParam, m.LParam,
(IRawElementProviderSimple)this);
return;
}
base.WndProc(ref m);
}