StatusBar.OnDrawItem(StatusBarDrawItemEventArgs) 方法

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

引发 OnDrawItem(StatusBarDrawItemEventArgs) 事件。

protected:
 virtual void OnDrawItem(System::Windows::Forms::StatusBarDrawItemEventArgs ^ sbdievent);

protected virtual void OnDrawItem (System.Windows.Forms.StatusBarDrawItemEventArgs sbdievent);

abstract member OnDrawItem : System.Windows.Forms.StatusBarDrawItemEventArgs -> unit
override this.OnDrawItem : System.Windows.Forms.StatusBarDrawItemEventArgs -> unit

Protected Overridable Sub OnDrawItem (sbdievent As StatusBarDrawItemEventArgs)

参数

sbdievent

StatusBarDrawItemEventArgs

包含事件数据的 StatusBarDrawItemEventArgs。

示例

下面的代码示例演示如何创建显示自定义背景和当前日期的所有者绘制 StatusBarPanel 。 此示例要求已将 DrawItem 控件的事件 StatusBar 连接到示例中定义的事件处理程序。

private:
   void DrawMyPanel( Object^ /*sender*/, System::Windows::Forms::StatusBarDrawItemEventArgs^ sbdevent )
   {
      // Create a StringFormat object to align text in the panel.
      StringFormat^ sf = gcnew StringFormat;

      // Format the String of the StatusBarPanel to be centered.
      sf->Alignment = StringAlignment::Center;
      sf->LineAlignment = StringAlignment::Center;

      // Draw a back blackground in owner-drawn panel.
      sbdevent->Graphics->FillRectangle( Brushes::Black, sbdevent->Bounds );

      // Draw the current date (short date format) with white text in the control's font.
      sbdevent->Graphics->DrawString( DateTime::Today.ToShortDateString(), statusBar1->Font, Brushes::White, sbdevent->Bounds, sf );
   }

private void DrawMyPanel(object sender, System.Windows.Forms.StatusBarDrawItemEventArgs sbdevent)
{
   // Create a StringFormat object to align text in the panel.
   StringFormat sf = new StringFormat();
   // Format the String of the StatusBarPanel to be centered.
   sf.Alignment = StringAlignment.Center;
   sf.LineAlignment = StringAlignment.Center;

   // Draw a black background in owner-drawn panel.
   sbdevent.Graphics.FillRectangle(Brushes.Black, sbdevent.Bounds);
   // Draw the current date (short date format) with white text in the control's font.
   sbdevent.Graphics.DrawString(DateTime.Today.ToShortDateString(), 
      statusBar1.Font,Brushes.White,sbdevent.Bounds,sf);
}

Private Sub StatusBar1_DrawItem(ByVal sender As Object, ByVal sbdevent As System.Windows.Forms.StatusBarDrawItemEventArgs) Handles StatusBar1.DrawItem

   ' Create a StringFormat object to align text in the panel.
   Dim sf As New StringFormat()
   ' Format the String of the StatusBarPanel to be centered.
   sf.Alignment = StringAlignment.Center
   sf.LineAlignment = StringAlignment.Center

   ' Draw a black background in owner-drawn panel.
   sbdevent.Graphics.FillRectangle(Brushes.Black, sbdevent.Bounds)
   ' Draw the current date (short date format) with white text in the control's font.
   sbdevent.Graphics.DrawString(DateTime.Today.ToShortDateString(), StatusBar1.Font, Brushes.White, _
         New RectangleF(sbdevent.Bounds.X, sbdevent.Bounds.Y, _
         sbdevent.Bounds.Width, sbdevent.Bounds.Height), sf)
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。

OnDrawItem 方法还允许派生类对事件进行处理而不必附加委托。 这是在派生类中处理事件的首选技术。

继承者说明

在派生类中重写 OnDrawItem(StatusBarDrawItemEventArgs) 时，一定要调用基类的 OnDrawItem(StatusBarDrawItemEventArgs) 方法，以便已注册的委托对事件进行接收。

另请参阅

• DrawItem
• StatusBarDrawItemEventArgs