获取gridview中EmptyDataTemplate（空模板）值
前台代码： <EmptyDataTemplate>
  <div id="head">
  <table style="width: 902px; height: 294px; background-color:Black;">
  <tr>
  <tr style="color:Silver;background-color:Black;font-weight:bold; width:5px; height:5px">
  <td scope="col">选择</td>
  <td scope="col">货号</td>
  <td scope="col">品名</td>
  <td scope="col">规格</td>
  <td scope="col">单位</td>
  <td scope="col">数量</td>
  <td scope="col">单价</td>
  <td scope="col">金额</td>
  <td scope="col">条码</td>
  <td scope="col">删除</td>
  </tr>
  <tr>
  <tr style="background-color:Silver; width:5px; height:5px;">
  <td scope="col"><asp:CheckBox ID="chk_Del" runat="server" /></td>
  <td scope="col" runat="server" id="lb1"></td>
  <td scope="col" runat="server" id="lb2"></td>
  <td scope="col" runat="server" id="lb3"></td>
  <td scope="col" runat="server" id="lb4"></td>
  <td scope="col" runat="server" id="lb5"></td>
  <td scope="col" runat="server" id="lb6"></td>
  <td scope="col" runat="server" id="lb7"></td>
  <td scope="col" runat="server" id="lb8"></td>
  <td scope="col"><asp:Button ID="btnDelete" runat="server" CssClass="button1" Text="刪除" CommandName="Del" OnClientClick="return window.confirm('您確定要刪除哱')" /></td>
  </tr>
  <tr>
  <tr style="background-color:Silver; width:5px; height:5px;">
  <td scope="col"><asp:CheckBox ID="CheckBox1" runat="server" /></td>
  <td scope="col" runat="server" id="lb9"></td>
  <td scope="col" runat="server" id="lb10"></td>
  <td scope="col" runat="server" id="lb11"></td>
  <td scope="col" runat="server" id="lb12"></td>
  <td scope="col" runat="server" id="lb13"></td>