MenuItem.OnClick(EventArgs) 方法
定义
重要
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引发 Click 事件。
protected:
virtual void OnClick(EventArgs ^ e);
protected virtual void OnClick (EventArgs e);
abstract member OnClick : EventArgs -> unit
override this.OnClick : EventArgs -> unit
Protected Overridable Sub OnClick (e As EventArgs)
参数
示例
下面的代码示例演示如何在单击 时MenuItem使用 Click 事件执行任务。 该示例创建一个名为 mainMenu1
的 ,并添加两MenuItem个 MainMenu 对象, topMenuItem
(File
) 和 menuItem1
(Open
) 。 然后, Click
它将事件连接到 menuItem1_Click
事件处理程序。 当用户单击菜单项时 Open
, OpenFileDialog 将初始化并显示 。 该示例要求你已创建名为 Form 的 Form1
。
public:
void CreateMyMenu()
{
// Create a main menu object.
MainMenu^ mainMenu1 = gcnew MainMenu;
// Create empty menu item objects.
MenuItem^ topMenuItem = gcnew MenuItem;
MenuItem^ menuItem1 = gcnew MenuItem;
// Set the caption of the menu items.
topMenuItem->Text = "&File";
menuItem1->Text = "&Open";
// Add the menu items to the main menu.
topMenuItem->MenuItems->Add( menuItem1 );
mainMenu1->MenuItems->Add( topMenuItem );
// Add functionality to the menu items using the Click event.
menuItem1->Click += gcnew System::EventHandler( this, &Form1::menuItem1_Click );
// Assign mainMenu1 to the form.
this->Menu = mainMenu1;
}
private:
void menuItem1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
// Create a new OpenFileDialog and display it.
OpenFileDialog^ fd = gcnew OpenFileDialog;
fd->DefaultExt = "*.";
fd->ShowDialog();
}
public void CreateMyMenu()
{
// Create a main menu object.
MainMenu mainMenu1 = new MainMenu();
// Create empty menu item objects.
MenuItem topMenuItem = new MenuItem();
MenuItem menuItem1 = new MenuItem();
// Set the caption of the menu items.
topMenuItem.Text = "&File";
menuItem1.Text = "&Open";
// Add the menu items to the main menu.
topMenuItem.MenuItems.Add(menuItem1);
mainMenu1.MenuItems.Add(topMenuItem);
// Add functionality to the menu items using the Click event.
menuItem1.Click += new System.EventHandler(this.menuItem1_Click);
// Assign mainMenu1 to the form.
this.Menu=mainMenu1;
}
private void menuItem1_Click(object sender, System.EventArgs e)
{
// Create a new OpenFileDialog and display it.
OpenFileDialog fd = new OpenFileDialog();
fd.DefaultExt = "*.*";
fd.ShowDialog();
}
Public Sub CreateMyMenu()
' Create a main menu object.
Dim mainMenu1 As New MainMenu()
' Create empty menu item objects.
Dim topMenuItem As New MenuItem()
Dim menuItem1 As New MenuItem()
' Set the caption of the menu items.
topMenuItem.Text = "&File"
menuItem1.Text = "&Open"
' Add the menu items to the main menu.
topMenuItem.MenuItems.Add(menuItem1)
mainMenu1.MenuItems.Add(topMenuItem)
' Add functionality to the menu items using the Click event.
AddHandler menuItem1.Click, AddressOf Me.menuItem1_Click
' Assign mainMenu1 to the form.
Me.Menu = mainMenu1
End Sub
Private Sub menuItem1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
' Create a new OpenFileDialog and display it.
Dim fd As New OpenFileDialog()
fd.DefaultExt = "*.*"
fd.ShowDialog()
End Sub
注解
引发事件时,将通过委托调用事件处理程序。 有关详细信息,请参阅 处理和引发事件。
继承者说明
在派生类中重写 OnClick(EventArgs) 时,请务必调用基类的 OnClick(EventArgs) 方法。