ActiveDesignerEventHandler 委托

表示将处理 ActiveDesignerChanged 事件的方法。

**命名空间:**System.ComponentModel.Design
**程序集:**System（在 system.dll 中）

语法

声明
Public Delegate Sub ActiveDesignerEventHandler ( _
    sender As Object, _
    e As ActiveDesignerEventArgs _
)
用法
Dim instance As New ActiveDesignerEventHandler(AddressOf HandlerMethod)

public delegate void ActiveDesignerEventHandler (
    Object sender,
    ActiveDesignerEventArgs e
)

public delegate void ActiveDesignerEventHandler (
    Object^ sender, 
    ActiveDesignerEventArgs^ e
)

/** @delegate */
public delegate void ActiveDesignerEventHandler (
    Object sender, 
    ActiveDesignerEventArgs e
)

JScript 支持使用委托，但不支持进行新的声明。

参数

• sender
  事件源。

• e
  包含事件数据的 ActiveDesignerEventArgs。

备注

ActiveDesignerChanged 事件在当前处于活动状态的文档经过修改时引发。

创建 ActiveDesignerEventHandler 委托时，标识将处理事件的方法。若要使该事件与事件处理程序相关联，请将该委托的一个实例添加到事件中。除非移除了该委托，否则每当发生该事件时就调用事件处理程序。有关事件处理程序委托的更多信息，请参见 事件和委托。

提示

应用于此类的 HostProtectionAttribute 属性 (Attribute) 具有以下 Resources 属性 (Property) 值：SharedState。HostProtectionAttribute 不影响桌面应用程序（桌面应用程序一般通过双击图标，键入命令或在浏览器中输入 URL 启动）。有关更多信息，请参见 HostProtectionAttribute 类或 SQL Server 编程和宿主保护属性。

示例

下面的示例演示如何注册 ActiveDesignerEventHandler 和处理 ActiveDesignerChanged 事件。

Public Sub LinkActiveDesignerEvent(ByVal eventService As IDesignerEventService)
    ' Registers an event handler for the ActiveDesignerChanged event.
    AddHandler eventService.ActiveDesignerChanged, AddressOf Me.OnActiveDesignerEvent
End Sub

Private Sub OnActiveDesignerEvent(ByVal sender As Object, ByVal e As ActiveDesignerEventArgs)
    ' Displays changed designer information on the console.            
    If Not (e.NewDesigner.RootComponent.Site Is Nothing) Then
        Console.WriteLine(("Name of the component of the new active designer: " + e.NewDesigner.RootComponent.Site.Name))
    End If
    Console.WriteLine(("Type of the component of the new active designer: " + e.NewDesigner.RootComponentClassName))
    If Not (e.OldDesigner.RootComponent.Site Is Nothing) Then
        Console.WriteLine(("Name of the component of the previously active designer: " + e.OldDesigner.RootComponent.Site.Name))
    End If
    Console.WriteLine(("Type of the component of the previously active designer: " + e.OldDesigner.RootComponentClassName))
End Sub

public void LinkActiveDesignerEvent(IDesignerEventService eventService)
{
    // Registers an event handler for the ActiveDesignerChanged event.
    eventService.ActiveDesignerChanged += new ActiveDesignerEventHandler(this.OnActiveDesignerEvent);
}

private void OnActiveDesignerEvent(object sender, ActiveDesignerEventArgs e)
{
    // Displays changed designer information on the console.
    if( e.NewDesigner.RootComponent.Site != null )
        Console.WriteLine("Name of the component of the new active designer: "+e.NewDesigner.RootComponent.Site.Name);            
    Console.WriteLine("Type of the component of the new active designer: "+e.NewDesigner.RootComponentClassName);
    if( e.OldDesigner.RootComponent.Site != null )
        Console.WriteLine("Name of the component of the previously active designer: "+e.OldDesigner.RootComponent.Site.Name);
    Console.WriteLine("Type of the component of the previously active designer: "+e.OldDesigner.RootComponentClassName);
}

public:
   void LinkActiveDesignerEvent( IDesignerEventService^ eventService )
   {
      // Registers an event handler for the ActiveDesignerChanged event.
      eventService->ActiveDesignerChanged += gcnew ActiveDesignerEventHandler( this, &MiscCompModSamples::ActiveDesignerEventHandlerExample::OnActiveDesignerEvent );
   }

private:
   void OnActiveDesignerEvent( Object^ /*sender*/, ActiveDesignerEventArgs^ e )
   {
      // Displays changed designer information on the console.
      if ( e->NewDesigner->RootComponent->Site != nullptr )
      {
         Console::WriteLine( "Name of the component of the new active designer: {0}", e->NewDesigner->RootComponent->Site->Name );
      }
      Console::WriteLine( "Type of the component of the new active designer: {0}", e->NewDesigner->RootComponentClassName );
      if ( e->OldDesigner->RootComponent->Site != nullptr )
      {
         Console::WriteLine( "Name of the component of the previously active designer: {0}", e->OldDesigner->RootComponent->Site->Name );
      }
      Console::WriteLine( "Type of the component of the previously active designer: {0}", e->OldDesigner->RootComponentClassName );
   }

public void LinkActiveDesignerEvent(IDesignerEventService eventService)
{
    // Registers an event handler for the ActiveDesignerChanged event.
    eventService.add_ActiveDesignerChanged(new ActiveDesignerEventHandler(
        this.OnActiveDesignerEvent));
} //LinkActiveDesignerEvent

private void OnActiveDesignerEvent(Object sender, ActiveDesignerEventArgs e)
{
    // Displays changed designer information on the console.
    if (e.get_NewDesigner().get_RootComponent().get_Site() != null) {
        Console.WriteLine("Name of the component of the new active designer: " 
            + e.get_NewDesigner().get_RootComponent().get_Site().get_Name());
    }
    Console.WriteLine("Type of the component of the new active designer: " 
        + e.get_NewDesigner().get_RootComponentClassName());
    if (e.get_OldDesigner().get_RootComponent().get_Site() != null) {
        Console.WriteLine("Name of the component of the previously active" 
            + " designer: " + e.get_OldDesigner().get_RootComponent().
            get_Site().get_Name());
    }
    Console.WriteLine("Type of the component of the previously active " 
        + " designer: " + e.get_OldDesigner().get_RootComponentClassName());
} //OnActiveDesignerEvent

平台

Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

System.ComponentModel.Design 命名空间
ActiveDesignerEventArgs 类
ActiveDesignerChanged