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

Определение

Вызывает событие 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)

Параметры

e
KeyEventArgs KeyEventArgs KeyEventArgs KeyEventArgs

Объект KeyEventArgs, содержащий данные события.A KeyEventArgs that contains the event data.

Примеры

В следующем примере кода KeyUp событие Help с классом используется для отображения всплывающей справки для пользователя.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

Комментарии

При возникновении события через делегат вызывается обработчик события.Raising an event invokes the event handler through a delegate. Дополнительные сведения см. в разделе обработка и вызов событий.For more information, see Handling and Raising Events.

Метод OnKeyUp также позволяет производным классам обрабатывать событие, не присоединяя делегат.The OnKeyUp method also allows derived classes to handle the event without attaching a delegate. Это предпочтительная методика обработки событий в производном классе.This is the preferred technique for handling the event in a derived class.

Примечания для тех, кто наследует этот метод

При переопределении метода OnKeyUp(KeyEventArgs) в производном классе нужно убедиться, что вызывается метод OnKeyUp(KeyEventArgs) базового класса, чтобы зарегистрированные делегаты получили событие.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.

Применяется к

Дополнительно