无法计算表达式,因为代码已优化或本机帧位于调用堆栈之上

时间:2012-11-26 11:44:00

标签: asp.net excel gridview download downloading

我在网格视图中有下载链接,当我点击它时,会弹出一个保存对话框,下载Excel填充。

但是我收到错误“无法评估表达式,因为代码已经过优化,或者本机框架位于调用堆栈之上。”在Response.End()

代码:

protected void grdFiles_RowCommand(object sender, GridViewCommandEventArgs e)
    {

        try
        {
            if (e.CommandName == "download")
            {
                string _FileName = Convert.ToString(e.CommandArgument);
                //Response.Clear();
                //Response.AppendHeader("Content-Disposition", "attachment; filename=" + _FileName);
                //Response.ContentType = "application//octet-stream";
                //Response.TransmitFile(Server.MapPath("~/Files/" + _FileName));
                //Response.End();

                // Get the physical Path of the file(test.doc)
                string filepath = Server.MapPath("test.doc");

                // Create New instance of FileInfo class to get the properties of the file being downloaded
                FileInfo file = new FileInfo(Server.MapPath("~/Files/" + _FileName));

                // Checking if file exists
                if (file.Exists)
                {
                    // Clear the content of the response
                    Response.ClearContent();

                    // LINE1: Add the file name and attachment, which will force the open/cance/save dialog to show, to the header
                    Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);

                    // Add the file size into the response header
                    Response.AddHeader("Content-Length", file.Length.ToString());

                    // Set the ContentType
                    Response.ContentType = "application/vnd.ms-excel";

                    // Write the file into the response (TransmitFile is for ASP.NET 2.0. In ASP.NET 1.1 you have to use WriteFile instead)
                    Response.TransmitFile(file.FullName);

                    // End the response
                    Response.End();
                }
            }
        }
        catch (Exception ex)
        {

        }
    }

4 个答案:

答案 0 :(得分:2)

此错误的另一个可能原因可能是因为您的网格位于更新面板中?

如果是这种情况,我建议您将网格控件添加为Post back触发器:

<asp:UpdatePanel runat="server" ID="UpdatePanel1">
    <Triggers>
        <asp:PostBackTrigger ControlID="grdFiles" />
    </Triggers>
    <ContentTemplate>
        <gridview ID="grdFiles" runat="server">
        your grid view content
        </gridview>
    </ContentTemplate>
</asp:UpdatePanel>

虽然将整个网格作为Post back触发器可能过度杀戮(可能会发生分页后退等),您可以尝试将下载链接创建为模板列,并将网格内的控件设置为回发触发器

我有一个类似的问题,我使用导出按钮作为下载按钮,并使用网格命令选择一个细节,只有当网格中的某些东西被选中后才能使这个按钮可用,然后在此处放置一个回发触发器按钮而不是在网格上。

答案 1 :(得分:0)

这是因为ThreadAbortException。尝试处理这个特定的例外。

   try
   {
      if (file.Exists)
      {
         //do something
      }
      response.End();
   }
   catch (ThreadAbortException ex)
   {
       //Log trace info
   }

答案 2 :(得分:0)

有一种方便的方法来处理&#34;无法评估表达式,因为代码已经过优化,或者本机框架位于调用堆栈之上。&#34;的问题。您需要在“输出”窗口中进行书写。

使用System.Diagnostics添加;

为错误的行添加Try / Catch

在Catch中添加这些行

try
{ ..}
catch(Exception ex)
{
    Debug.WriteLine(ex.Message);
    Debug.WriteLine(ex.StackTrace);
    Debug.WriteLine(ex.InnerException.ToString());
}

只需调试并检查输出窗口

希望它有所帮助。

答案 3 :(得分:-1)

将文件路径存储在Web.Config文件中并尝试以下代码:

    string filename = "test.doc";
    string FilePath = ConfigurationManager.AppSettings.Get("SharedPath") + ConfigurationManager.AppSettings.Get("Path") + "\\\\" + filename;

    FileInfo file = new FileInfo(FilePath);
    if (file.Exists)
    {
        Response.AppendHeader("content-disposition",
        "attachment; filename=" + filename);
        Response.ContentType = "application/download";
        Response.WriteFile(FilePath);
        Response.End();
    }