GridView Export Issue

Question

在下面的代码中，我有一个网格视图，它绑定了我想要以excel格式导出数据的数据。但我无法导出，请帮助我解决问题。网格视图是放置在更新面板内。

<asp:UpdateProgress ID="UpdateProgress2" AssociatedUpdatePanelID="HoardReportPanel" runat="server"> 
       <ProgressTemplate> 
        Details are loading... Please wait 
       </ProgressTemplate> 
      </asp:UpdateProgress> 
      <asp:UpdatePanel ID="HoardReportPanel" runat="server"> 
       <ContentTemplate> 
    <asp:GridView Width="100%" runat="server" ID="GridOpenstk" AutoGenerateColumns="false" CellPadding="4" ForeColor="#333333" ShowFooter="false" 
         PageSize-Mode="NumericPages" PageSize="10" PagerStyle-Visible="true" BackColor="AliceBlue" AllowPaging="true" AllowSorting="true" 
         OnPageIndexChanging="GridOpenstk_PageIndex" 
         CssClass="mGrid" 
         PagerStyle-CssClass="pgr" AlternatingRowStyle-CssClass="alt" Visible="false" > 
         <Columns>     

         <asp:TemplateField HeaderText="Location" ItemStyle-Width="200px" >    
          <ItemTemplate>            
           <asp:Label ID="lbllocation" runat="server" Text='<%#Eval("location") %>' > </asp:Label> 
          </ItemTemplate> 
         </asp:TemplateField> 
         <asp:TemplateField HeaderText="ProductName" ItemStyle-Width="200px" >    
          <ItemTemplate>            
           <asp:Label ID="lblProductName" runat="server" Text='<%#Eval("ProductName") %>' > </asp:Label> 
          </ItemTemplate> 
         </asp:TemplateField> 
         <asp:TemplateField HeaderText="OpeningStock" itemstyle-width="150px"> 
          <ItemTemplate>            
           <asp:Label ID="lblOpeningStock" runat="server" Text='<%#Eval("OpeningStock") %>' > </asp:Label> 
          </ItemTemplate>  
         </asp:TemplateField> 


         </Columns>   
         <HeaderStyle Font-Bold="True" ForeColor="White" /> 
         </asp:GridView> 
         <asp:Button ID="btnExportExcel" OnClick="btnExportExcel_Click" runat="server" Text="Export Excel" /> 
    </ContentTemplate> 
       </asp:UpdatePanel> 


    protected void btnExportExcel_Click(object sender, EventArgs e) 
      { 
       HtmlForm form = new HtmlForm(); 
       Response.Clear(); 
       Response.Buffer = true; 
       Response.Charset = ""; 
       Response.AddHeader("content-disposition", string.Format("attachment;filename={0}", "Student.xls")); 
       Response.ContentType = "application/ms-excel"; 
       StringWriter sw = new StringWriter(); 
       HtmlTextWriter hw = new HtmlTextWriter(sw); 
       GridOpenstk.AllowPaging = false; 
       string location = ddlLocation.SelectedValue; 
       string startdate = Convert.ToDateTime(txtFromDate.Text + " 00:00:00").ToString("yyyy-MM-dd" + " 00:00:00"); 
       string enddate = Convert.ToDateTime(txtToDate.Text + " 23:59:59").ToString("yyyy-MM-dd" + " 00:00:00"); 
       MastersClient OpeningStock = new MastersClient(); 
       DataSet ds = OpeningStock.GetOpeningStockReport(location, startdate, enddate); 
       GridOpenstk.DataSource = ds; 
       GridOpenstk.DataBind(); 
       form.Attributes["runat"] = "server"; 
       form.Controls.Add(GridOpenstk); 
       this.Controls.Add(form); 
       form.RenderControl(hw); 
       string style = @"<style> .textmode { mso-number-format:\@;}</style>"; 
       Response.Write(style); 
       Response.Output.Write(sw.ToString()); 
       Response.Flush(); 
       Response.End(); 
      } 

      public override void VerifyRenderingInServerForm(Control control) 
      { 
       /* Verifies that the control is rendered */ 
      } 

Answer 1

如果GridView被置于UpdatePanel里面，你必须确保你已经创建了该按钮的全PostBackTrigger：

<asp:UpdatePanel ID="HoardReportPanel" runat="server"> 
    <ContentTemplate> 
     .. grid ... 
     <asp:Button ID="btnExportExcel" OnClick="btnExportExcel_Click" runat="server" Text="Export Excel" /> 
    </ContentTemplate> 
    <Triggers> 
     <asp:PostBackTrigger ControlID="btnExportExcel" /> 
    </Triggers> 
</asp:UpdatePanel>