ComponentEventHandler Delegato

Definizione

public delegate void ComponentEventHandler(System::Object ^ sender, ComponentEventArgs ^ e);

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

public delegate void ComponentEventHandler(object sender, ComponentEventArgs e);

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

type ComponentEventHandler = delegate of obj * ComponentEventArgs -> unit

Public Delegate Sub ComponentEventHandler(sender As Object, e As ComponentEventArgs)

Parametri

Attributi

ComVisibleAttribute

Esempio

Nell'esempio seguente viene illustrata la registrazione di un oggetto ComponentEventHandler e la gestione degli ComponentAddedeventi , ComponentAddingComponentRemoved e ComponentRemoving .

public:
   void LinkComponentEvent( IComponentChangeService^ changeService )
   {
      // Registers an event handler for the ComponentAdded,
      // ComponentAdding, ComponentRemoved, and ComponentRemoving events.
      changeService->ComponentAdded += gcnew ComponentEventHandler(
         this, &ComponentEventHandlerExample::OnComponentEvent );
      changeService->ComponentAdding += gcnew ComponentEventHandler(
         this, &ComponentEventHandlerExample::OnComponentEvent );
      changeService->ComponentRemoved += gcnew ComponentEventHandler(
         this, &ComponentEventHandlerExample::OnComponentEvent );
      changeService->ComponentRemoving += gcnew ComponentEventHandler(
         this, &ComponentEventHandlerExample::OnComponentEvent );
   }

private:
   void OnComponentEvent( Object^ sender, ComponentEventArgs^ e )
   {
      // Displays changed component information on the console.
      if ( e->Component->Site != nullptr )
      {
         Console::WriteLine( "Name of the component related to the event: " +
            e->Component->Site->Name );
      }
      Console::WriteLine( "Type of the component related to the event: " +
         e->Component->GetType()->FullName );
   }

public void LinkComponentEvent(IComponentChangeService changeService)
{
    // Registers an event handler for the ComponentAdded,
    // ComponentAdding, ComponentRemoved, and ComponentRemoving events.
    changeService.ComponentAdded += new ComponentEventHandler(this.OnComponentEvent);            
    changeService.ComponentAdding += new ComponentEventHandler(this.OnComponentEvent);            
    changeService.ComponentRemoved += new ComponentEventHandler(this.OnComponentEvent);            
    changeService.ComponentRemoving += new ComponentEventHandler(this.OnComponentEvent);                        
}

private void OnComponentEvent(object sender, ComponentEventArgs e)
{
    // Displays changed component information on the console.            
    if( e.Component.Site != null )
        Console.WriteLine("Name of the component related to the event: "+e.Component.Site.Name);      
    Console.WriteLine("Type of the component related to the event: "+e.Component.GetType().FullName);
}

Public Sub LinkComponentEvent(ByVal changeService As IComponentChangeService)
    ' Registers an event handler for the ComponentAdded,
    ' ComponentAdding, ComponentRemoved, and ComponentRemoving events.
    AddHandler changeService.ComponentAdded, AddressOf Me.OnComponentEvent
    AddHandler changeService.ComponentAdding, AddressOf Me.OnComponentEvent
    AddHandler changeService.ComponentRemoved, AddressOf Me.OnComponentEvent
    AddHandler changeService.ComponentRemoving, AddressOf Me.OnComponentEvent
End Sub

Private Sub OnComponentEvent(ByVal sender As Object, ByVal e As ComponentEventArgs)
    ' Displays changed component information on the console.            
    If (e.Component.Site IsNot Nothing) Then
        Console.WriteLine(("Name of the component related to the event: " + e.Component.Site.Name))
    End If
End Sub

Commenti

Quando si crea un ComponentEventHandler delegato, si identifica il metodo che gestirà l'evento. Per associare l'evento al gestore eventi, aggiungere un'istanza del delegato all'evento. Il gestore eventi viene chiamato ogni volta che si verifica l'evento, a meno che non si rimuovono il delegato. Per altre informazioni sui delegati del gestore eventi, vedere Gestione e generazione di eventi.

Vedi anche

• ComponentEventArgs
• ComponentChangingEventHandler
• ComponentChangedEventHandler