ComponentChangedEventHandler Делегат

Определение

public delegate void ComponentChangedEventHandler(System::Object ^ sender, ComponentChangedEventArgs ^ e);

public delegate void ComponentChangedEventHandler(object? sender, ComponentChangedEventArgs e);

public delegate void ComponentChangedEventHandler(object sender, ComponentChangedEventArgs e);

[System.Runtime.InteropServices.ComVisible(true)]
public delegate void ComponentChangedEventHandler(object sender, ComponentChangedEventArgs e);

type ComponentChangedEventHandler = delegate of obj * ComponentChangedEventArgs -> unit

[<System.Runtime.InteropServices.ComVisible(true)>]
type ComponentChangedEventHandler = delegate of obj * ComponentChangedEventArgs -> unit

Public Delegate Sub ComponentChangedEventHandler(sender As Object, e As ComponentChangedEventArgs)

Параметры

Атрибуты

ComVisibleAttribute

Примеры

В этом примере демонстрируется регистрация ComponentChangedEventHandler и обработка ComponentChanged события.

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.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 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

Комментарии

При создании делегата ComponentChangedEventHandler вы определите метод, который будет обрабатывать событие. Чтобы связать событие с обработчиком событий, добавьте экземпляр делегата в событие. Обработчик событий вызывается всякий раз, когда происходит событие, если вы не удалите делегат. Дополнительные сведения о делегатах обработчика событий см. в разделе "Обработка и создание событий".

Событие ComponentChanged не будет происходить во время загрузки или выгрузки формы, так как изменения ожидаются во время этих операций.

См. также раздел

• ComponentChanged
• ComponentChanging
• ComponentChangedEventArgs
• IComponentChangeService