Databases
StackOverflow2013
Postsdbo
POCalling Response.TransmitFile() from static method
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POCalling Response.TransmitFile() from static method
    primarykey
    data
    text
    <p>I have a number of pages which need to support exporting data to an Excel spreadsheet. I can generate the Excel files just fine, but I'm trying to work out how to abstract this behavior so it's easily reusable from all of the pages where I need it. My current idea is to use a static utility method, as follows:</p> <pre><code>public static void SendExcelFile(System.Web.UI.Page callingPage, string downloadFileName, List&lt;List&lt;string&gt;&gt; data, string worksheetTitle) { string tempFileName = Path.GetTempFileName(); try { // Generate file using ExcelPackage GenerateExcelDoc(tempFileName, data, worksheetTitle); callingPage.Response.AddHeader("Content-Disposition", "attachment;filename=" + downloadFileName); callingPage.Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"; callingPage.Response.AddHeader("Content-Length", new FileInfo(tempFileName).Length.ToString()); callingPage.Response.TransmitFile(tempFileName); } finally { //When this is removed, the method works as expected. if (File.Exists(tempFileName)) File.Delete(tempFileName); } } </code></pre> <p>The click handler where I'm calling <code>SendExcelFile</code> looks like this:</p> <pre><code>protected void lnkExport_Click(object sender, EventArgs e) { List&lt;List&lt;string&gt;&gt; dataList = GatherDataForSpreadsheet(); Utility.SendExcelFile(this, "fileNameForDownload.xlsx", dataList, "MyReports"); } </code></pre> <p>This code works just fine as an instance method of the calling page. As a static method, though, it doesn't work at all. When I click the button that invokes this, the browser shows the loading animations indefinitely, but never prompts for a file download.</p> <p>I'm very new to ASP.NET (and web programming in general), so I'm sure I'm missing something here. Could someone please explain the behavior I'm seeing, and suggest a reasonable alternative to this approach?</p> <p>EDIT: If I remove the call to File.Delete() at the end, the method works as expected. Does Response.TransmitFile() do the transfer asynchronously?</p> <p>EDIT 2: I just needed to call Response.Flush() before I deleted the file. See my answer below. Thanks!</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USOdrade
    1. USOdrade
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POCalling Response.TransmitFile() from static method
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POCalling Response.TransmitFile() from static method
      1. This table or related slice is empty.
      1. VTUpMod
    1. COHave you walked through the code in debug mode? If so, can you tell where it's timing out (or if it's even entering this method)? Is your `SendExcelFile` method throwing an exception? If so, please add the exception's stack trace, which might help us get to the bottom of this. Oh, and a sample call to this method would be helpful too (perhaps your click handler).
      singulars
      1. POCalling Response.TransmitFile() from static method
      1. USJeff Sternal
    2. COI have debugged through it. The SendExcelFile method seems to execute normally and then exits, but the browser never prompts for the file download. The tab in IE or Firefox shows the loading animation, and there is a page load progress bar at the bottom of the browser. The page itself remains responsive.
      singulars
      1. POCalling Response.TransmitFile() from static method
      1. USOdrade
    3. COI could post the click handler if you want, but I doubt it would be helpful. In short, it's just: var data = GenerateData(); Utility.SendExcelFile(data);
      singulars
      1. POCalling Response.TransmitFile() from static method
      1. USOdrade
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload