MenuItem.OnSelect(EventArgs) 方法

protected:
 virtual void OnSelect(EventArgs ^ e);

protected virtual void OnSelect(EventArgs e);

abstract member OnSelect : EventArgs -> unit
override this.OnSelect : EventArgs -> unit

Protected Overridable Sub OnSelect (e As EventArgs)

參數

範例

以下程式碼範例示範如何利用Select類別事件MenuItem將說明文字指派到控制項的 StatusBarPanel aStatusBar。 此範例要求MenuItem在表單上的控制項中加入menuOpen名為 menuSave、 menuExit和 MainMenu 的物件。 範例還要求表單中新增一個 StatusBar 名為 statusBar1 named 的控制項。 StatusBar控制點應包含一個 StatusBarPanel。

private:
   void MenuSelected( Object^ sender, System::EventArgs^ /*e*/ )
   {
      if ( sender == menuOpen )
            statusBar1->Panels[ 0 ]->Text = "Opens a file to edit";
      else
      if ( sender == menuSave )
            statusBar1->Panels[ 0 ]->Text = "Saves the current file";
      else
      if ( sender == menuExit )
            statusBar1->Panels[ 0 ]->Text = "Exits the application";
      else
            statusBar1->Panels[ 0 ]->Text = "Ready";
   }

private void MenuSelected(object sender, System.EventArgs e)
{
   if (sender == menuOpen)
      statusBar1.Panels[0].Text = "Opens a file to edit";
   else if(sender == menuSave)
      statusBar1.Panels[0].Text = "Saves the current file";
   else if(sender == menuExit)
      statusBar1.Panels[0].Text = "Exits the application";
   else
      statusBar1.Panels[0].Text = "Ready";
}

Private Sub MenuSelected(ByVal sender As Object, ByVal e As System.EventArgs) _
                     Handles menuOpen.Select, menuExit.Select, menuSave.Select
   If sender Is menuOpen Then
      StatusBar1.Panels(0).Text = "Opens a file to edit"
   Else
      If sender Is menuSave Then
         StatusBar1.Panels(0).Text = "Saves the current file"
      Else
         If sender Is menuExit Then
            StatusBar1.Panels(0).Text = "Exits the application"
         Else
            StatusBar1.Panels(0).Text = "Ready"
         End If
      End If
   End If
End Sub

備註

發起事件會透過代理呼叫事件處理者。 欲了解更多資訊，請參閱 處理與提升事件。

給繼承者的注意事項

在導出類別中覆 OnSelect(EventArgs) 寫時，務必呼叫基底類別的方法 OnSelect(EventArgs) 。