protected void btnDelete_Click(object sender, EventArgs e)
 {
     try
     {
         for (int i = 0; i < gvMain.Rows.Count; i++)
         {
             if (gvMain.Rows[0].Cells[0].Text == "没有符合以上条件的数据,请重新查询 ")
             {
                 break;
             }
             else
             {
                 CheckBox chk = (CheckBox)gvMain.Rows[i].Cells[0].Controls[0];
                 if (chk.Enabled && chk.Checked)
                 {
                     dsClass.Tables[0].Rows[i].Delete();
                 }
             }
         }
         objClass.Delete(dsClass);
         totalCount        = objClass.GetRowCount(filter);
         pager.RecordCount = totalCount;
         if (pageIndex > pager.PageCount)
         {
             pageIndex = pager.PageCount;
         }
         GridDataBind();
     }
     catch (Exception exp)
     {
         JScript.Instance.ShowMessage(this.UpdatePanel1, exp.Message);
     }
 }