关于中gridview 字符串截取的方法

<style  type="text/css"> 
 .listover150 
{ 
width:150px; 
text-align:left; 
overflow:hidden; 
text-overflow:ellipsis;//超长设置省略号 
white-space:nowrap; 
} 
</style> 

 //列表加载处理 
   protected void gv_showReport_RowDataBound(object sender, GridViewRowEventArgs e) 
   { 

       if (e.Row.RowType == DataControlRowType.DataRow) 
       { 

           //当鼠标移开时还原背景色 
           e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor=c"); 
           e.Row.Attributes.Add("onmouseover", "c=this.style.backgroundColor;this.style.backgroundColor=#F4FBFF"); 
           e.Row.Attributes.Add("onclick", "this.style.backgroundColor=#e2eaf1"); 
       } 
       if (e.Row.RowType == DataControlRowType.Header) 
       { 
           e.Row.Attributes.Add("style", "background-image:url(../images/grid3-hrow.gif)"); 
       } 
       if (e.Row.RowType == DataControlRowType.DataRow) 
       { 
           //设置申请原因字符串显示长度 
           string strDISC = e.Row.Cells[4].Text.Trim(); 
           e.Row.Cells[4].Text = "<div class=/"listover150/">" + strDISC + "</div>"; 
           e.Row.Cells[4].ToolTip = strDISC;//鼠标放上去显示所有 

           //设置审批备注字符串截取长度 
           string str = e.Row.Cells[7].Text.Trim(); 
           e.Row.Cells[7].Text = "<div class=/"listover150/">" + str + "</div>"; 
           e.Row.Cells[7].ToolTip = str; 

       } 
   }