Can't return word document, generated in memory stream, for downloading to user - asp.net

Question

I've got a problem while resolving one task. The task was: Create an opportunity for users to download a .docx document with pasted data. But I'm stuck at the moment at sending the file as a byte array (taken from a MemoryStream) to the context's response. Here's a sample:
using (MemoryStream stream = new MemoryStream(FileBytes))
{
using (WordprocessingDocument myDoc = WordprocessingDocument.Open(stream, true))
{
MainDocumentPart mainPart = myDoc.MainDocumentPart;
foreach (SdtElement obj in mainPart.Document.Body.Descendants<SdtElement>().ToList())
{
foreach (Text t in obj.Descendants<Text>().ToList())
{
switch (t.Text)
{
//.... here is code that fiiling content control's
}
}
}
myDoc.MainDocumentPart.Document.Save();
myDoc.Close();
}
context.Response.Clear();
context.Response.ClearHeaders();
context.Response.ClearContent();
context.Response.AddHeader("content-disposition", "attachment; filename=\"" + DocName + ".docx\"");
context.Response.ContentType = "application/vnd.openxmlformats-officedocument.wordprocessingml.document";
context.Response.ContentEncoding = Encoding.GetEncoding("ISO-8859-1");
stream.Seek(0, SeekOrigin.Begin);
context.Response.BinaryWrite(stream.ToArray());
}
context.Response.Flush();
The HTTP handler doesn't return any errors - page refresh and download don't start. The handler is calling from JS. Here is the sample of the JS function:
function save_word_doc(id_btn) {
// ... here is code that gets params from default page data
jQuery.post("DataHandler.ashx?CN=" + vCN + "&CommandName=SaveWord&auctionID=" + oFormRecord.auctionID
+ "&user_login=" + user_login
+ ....
+ "&amount=" + oFormRecord.value.amount
+ "&percent=" + percent);
}
By the way, this sample code is working well in an ASP.Net MVC project, where the handler is calling from a link button. But this must work in a Web Forms project.
Update to pretend questions and incorrect answers: the file is generated and saved correctly to the local machine.

Answer 1

I see a few issues in your code. Firstly, new MemoryStream(FileBytes) creates a non-resizable MemoryStream, which is not what you want in case you are changing the WordprocessingDocument. You would should use new MemoryStream() to create a resizable MemoryStream and copy your FileBytes to that MemoryStream.
Secondly, since you are in a using statement, you don't need the following two lines of code. This is done automatically for you.
myDoc.MainDocumentPart.Document.Save();
myDoc.Close();
Lastly, I am not sure about your ContentEncoding value for the binary data you are sending. You might want to use a tool like Fiddler or Postman to verify what happens.