显示DataGrid序号的一个适用的方法

override protected void OnPaint(PaintEventArgs e)<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
{
base.OnPaint(e);
 try
 {
  if(this.DataSource!=null)
 { 
 int yDelta; 
 System.Drawing .Rectangle cell=this.GetCellBounds(0,0);
 int y=cell.Top +2;
 e.Graphics.DrawString("编号", this.Font, new SolidBrush(Color.Black), 8, y-18); //
 if(this.VisibleRowCount >0)//只在有记录集时在表格中显示序号
 {  
 CurrencyManager cm;
 cm = (CurrencyManager) this.BindingContext[this.DataSource, this.DataMember]; 
 if(cm.Count >0)
 { 
 int nRow=-1;
 y=41; //为第一行默认高度
 while(nRow<0)
 {
nRow=this.HitTest (8,y).Row ;
 y++;
 }
 int nCount=0;
 while(y<this.Height && nCount<this.VisibleRowCount )
 {
 string text = string.Format("{0}", nRow+nCount+1); 
 e.Graphics.DrawString(text, this.Font, new SolidBrush(Color.Black), 10, y); 
 yDelta = this.GetCellBounds( nRow+nCount,0).Height + 1;//****表示一行高度的参数
 y += yDelta; 
//如果下面有子行显示序号的区分显示 
 if(this.IsExpanded (nRow+nCount)&& nRow+nCount+1<cm.Count )    {
 y+=this.GetCellBounds (nRow+nCount+1,0).Height +3;
 }
 nCount++;  
 }
}
 }
 }
 }
 catch
 {}
}