Control.OnKeyUp(KeyEventArgs) Control.OnKeyUp(KeyEventArgs) Control.OnKeyUp(KeyEventArgs) Control.OnKeyUp(KeyEventArgs) Method

Definizione

Genera l'evento KeyUp.Raises the KeyUp event.

protected:
 virtual void OnKeyUp(System::Windows::Forms::KeyEventArgs ^ e);
protected virtual void OnKeyUp (System.Windows.Forms.KeyEventArgs e);
abstract member OnKeyUp : System.Windows.Forms.KeyEventArgs -> unit
override this.OnKeyUp : System.Windows.Forms.KeyEventArgs -> unit
Protected Overridable Sub OnKeyUp (e As KeyEventArgs)

Parametri

e
KeyEventArgs KeyEventArgs KeyEventArgs KeyEventArgs

Oggetto KeyEventArgs che contiene i dati dell'evento.A KeyEventArgs that contains the event data.

Esempi

Nell'esempio di codice seguente viene KeyUp usato l'evento Help con la classe per visualizzare la Guida di tipo popup per l'utente.The following code example uses the KeyUp event with the Help class to display pop-up style help to the user.

   // This example demonstrates how to use the KeyUp event with the Help class to display
   // pop-up style help to the user of the application. When the user presses F1, the Help
   // class displays a pop-up window, similar to a ToolTip, near the control. This example assumes
   // that a TextBox control, named textBox1, has been added to the form and its KeyUp
   // event has been connected to this event handler method.
private:
   void textBox1_KeyUp( Object^ /*sender*/, System::Windows::Forms::KeyEventArgs^ e )
   {
      
      // Determine whether the key entered is the F1 key. Display help if it is.
      if ( e->KeyCode == Keys::F1 )
      {
         
         // Display a pop-up help topic to assist the user.
         Help::ShowPopup( textBox1, "Enter your first name", Point(textBox1->Right,this->textBox1->Bottom) );
      }
   }
// This example demonstrates how to use the KeyUp event with the Help class to display
// pop-up style help to the user of the application. When the user presses F1, the Help
// class displays a pop-up window, similar to a ToolTip, near the control. This example assumes
// that a TextBox control, named textBox1, has been added to the form and its KeyUp
// event has been contected to this event handler method.
private void textBox1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
{
    // Determine whether the key entered is the F1 key. Display help if it is.
    if(e.KeyCode == Keys.F1)
    {
        // Display a pop-up help topic to assist the user.
        Help.ShowPopup(textBox1, "Enter your first name", new Point(textBox1.Right, this.textBox1.Bottom));
    }
}
' This example demonstrates how to use the KeyUp event with the Help class to display
' pop-up style help to the user of the application. When the user presses F1, the Help
' class displays a pop-up window, similar to a ToolTip, near the control. This example assumes
' that a TextBox control, named textBox1, has been added to the form and its KeyUp
' event has been contected to this event handler method.
Private Sub textBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles textBox1.KeyUp
    ' Determine whether the key entered is the F1 key. Display help if it is.
    If e.KeyCode = Keys.F1 Then
        ' Display a pop-up help topic to assist the user.
        Help.ShowPopup(textBox1, "Enter your first name", New Point(textBox1.Right, Me.textBox1.Bottom))
    End If
End Sub

Commenti

Quando viene generato un evento, il gestore dell'evento viene richiamato tramite un delegato.Raising an event invokes the event handler through a delegate. Per altre informazioni, vedere la gestione e generazione di eventi.For more information, see Handling and Raising Events.

Il metodo OnKeyUp consente inoltre alle classi derivate di gestire l'evento senza associare un delegato.The OnKeyUp method also allows derived classes to handle the event without attaching a delegate. È la tecnica consigliata per la gestione dell'evento in una classe derivata.This is the preferred technique for handling the event in a derived class.

Note per gli eredi

Quando si esegue l'override di OnKeyUp(KeyEventArgs) in una classe derivata, verificare di chiamare il metodo OnKeyUp(KeyEventArgs) della classe di base in modo che i delegati registrati ricevano l'evento.When overriding OnKeyUp(KeyEventArgs) in a derived class, be sure to call the base class's OnKeyUp(KeyEventArgs) method so that registered delegates receive the event.

Si applica a

Vedi anche