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;  

       }  
   }