鼠标放上显示完全内容

//显示单元格内容
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
     DataRowView drv = (DataRowView)e.Item.DataItem;
     string sign1 = Convert.ToString(drv["GHDW"]);
     e.Item.Cells[1].Attributes.Add("title",sign1.Trim());
    }