StatusBar.DrawItem 事件

当所有者描述的状态栏控件的可视特征发生变化时，发生此事件。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Event DrawItem As StatusBarDrawItemEventHandler
用法
Dim instance As StatusBar
Dim handler As StatusBarDrawItemEventHandler

AddHandler instance.DrawItem, handler

public event StatusBarDrawItemEventHandler DrawItem

public:
event StatusBarDrawItemEventHandler^ DrawItem {
    void add (StatusBarDrawItemEventHandler^ value);
    void remove (StatusBarDrawItemEventHandler^ value);
}

/** @event */
public void add_DrawItem (StatusBarDrawItemEventHandler value)

/** @event */
public void remove_DrawItem (StatusBarDrawItemEventHandler value)

JScript 支持使用事件，但不支持进行新的声明。

备注

可以使用此事件在所有者描述的 StatusBar 控件中执行描述操作。例如，若显示所有者描述的 StatusBarPanel（显示进度栏），则可以使用此事件在面板上执行进度栏的描述操作。使用通过 StatusBarDrawItemEventArgs 对象提供给事件并同时作为参数传递给事件处理程序的数据，可确定需要描述的面板和用来描述面板的 Graphics 对象。只有 StatusBar 控件中 StatusBarPanel 的 StatusBarPanel.Style 属性设置成 OwnerDraw 时才引发此事件。

有关处理事件的更多信息，请参见 使用事件。

示例

下面的代码示例演示如何创建所有者描述的 StatusBarPanel，它显示自定义背景和当前日期。本示例要求已将 StatusBar 控件的 DrawItem 事件连接到本示例中定义的事件处理程序。

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

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:
   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.set_Alignment(StringAlignment.Center);
    sf.set_LineAlignment(StringAlignment.Center);
    // Draw a back blackground in owner-drawn panel.
    sbdEvent.get_Graphics().FillRectangle(Brushes.get_Black(), 
        sbdEvent.get_Bounds());
    // Draw the current date (short date format) with white text 
    // in the control's font.
    sbdEvent.get_Graphics().DrawString(DateTime.get_Today().
        ToShortDateString(), statusBar1.get_Font(), Brushes.get_White(),
        RectangleF.op_Implicit(sbdEvent.get_Bounds()), sf);
} //DrawMyPanel

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

StatusBar 类
StatusBar 成员
System.Windows.Forms 命名空间
OnDrawItem
StatusBarDrawItemEventArgs
StatusBarDrawItemEventHandler