ComponentChangedEventHandler 委托

表示将处理 ComponentChanged 事件的方法。

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

语法

声明
<ComVisibleAttribute(True)> _
Public Delegate Sub ComponentChangedEventHandler ( _
    sender As Object, _
    e As ComponentChangedEventArgs _
)
用法
Dim instance As New ComponentChangedEventHandler(AddressOf HandlerMethod)

[ComVisibleAttribute(true)] 
public delegate void ComponentChangedEventHandler (
    Object sender,
    ComponentChangedEventArgs e
)

[ComVisibleAttribute(true)] 
public delegate void ComponentChangedEventHandler (
    Object^ sender, 
    ComponentChangedEventArgs^ e
)

/** @delegate */
/** @attribute ComVisibleAttribute(true) */ 
public delegate void ComponentChangedEventHandler (
    Object sender, 
    ComponentChangedEventArgs 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 ComponentChangedEventArgs。

备注

当创建 ComponentChangedEventHandler 委托时，将标识处理事件的方法。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。

在加载或卸载窗体的过程中，由于需要进行更改，将不会引发 ComponentChanged 事件。

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

此示例说明如何注册 ComponentChangedEventHandler 和处理 ComponentChanged 事件。

Public Sub LinkComponentChangedEvent(ByVal changeService As IComponentChangeService)
    ' Registers an event handler for the ComponentChanged event.
    AddHandler changeService.ComponentChanged, AddressOf Me.OnComponentChanged
End Sub

Private Sub OnComponentChanged(ByVal sender As Object, ByVal e As ComponentChangedEventArgs)
    ' Displays changed component information on the console.            
    Console.WriteLine(("Type of the component that has changed: " + e.Component.GetType().FullName))
    Console.WriteLine(("Name of the member of the component that has changed: " + e.Member.Name))
    Console.WriteLine(("Old value of the member: " + e.OldValue.ToString()))
    Console.WriteLine(("New value of the member: " + e.NewValue.ToString()))
End Sub

public void LinkComponentChangedEvent(IComponentChangeService changeService)
{
    // Registers an event handler for the ComponentChanged event.
    changeService.ComponentChanged += new ComponentChangedEventHandler(this.OnComponentChanged);            
}

private void OnComponentChanged(object sender, ComponentChangedEventArgs e)
{
    // Displays changed component information on the console.
    Console.WriteLine("Type of the component that has changed: "+e.Component.GetType().FullName);      
    Console.WriteLine("Name of the member of the component that has changed: "+e.Member.Name);            
    Console.WriteLine("Old value of the member: "+e.OldValue.ToString());
    Console.WriteLine("New value of the member: "+e.NewValue.ToString());
}

public:
   void LinkComponentChangedEvent( IComponentChangeService^ changeService )
   {
      // Registers an event handler for the ComponentChanged event.
      changeService->ComponentChanged += gcnew ComponentChangedEventHandler(
         this, &ComponentChangedEventHandlerExample::OnComponentChanged );
   }

private:
   void OnComponentChanged( Object^ sender, ComponentChangedEventArgs^ e )
   {
      // Displays changed component information on the console.
      Console::WriteLine( "Type of the component that has changed: " +
         e->Component->GetType()->FullName );
      Console::WriteLine( "Name of the member of the component that has changed: " +
         e->Member->Name );
      Console::WriteLine( "Old value of the member: " + e->OldValue );
      Console::WriteLine( "New value of the member: " + e->NewValue );
   }

public void LinkComponentChangedEvent(IComponentChangeService changeService)
{
    // Registers an event handler for the ComponentChanged event.
    changeService.add_ComponentChanged(new 
        ComponentChangedEventHandler(this.OnComponentChanged));
} //LinkComponentChangedEvent

private void OnComponentChanged(Object sender, ComponentChangedEventArgs e)
{
    // Displays changed component information on the console.
    Console.WriteLine("Type of the component that has changed: " 
        + e.get_Component().GetType().get_FullName());
    Console.WriteLine("Name of the member of the component "
        + "that has changed: " + e.get_Member().get_Name());
    Console.WriteLine("Old value of the member: " 
        + e.get_OldValue().ToString());
    Console.WriteLine("New value of the member: " 
        + e.get_NewValue().ToString());
} //OnComponentChanged

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
ComponentChanged
ComponentChanging
ComponentChangedEventArgs 类
IComponentChangeService