How to get content from FileStreamResult

Question

I am using a third party library in which one of the methods returns FileStreamResult.

public FileStreamResult GenerateFile(OutFormat format, dynamic params);

An action in my controller calls this method:

public ActionResult GenerateExcel()
{
    Utils.XCore core = new Utils.XCore(...); // where ... are contructor params
    // ... other codes here ...
    return core.GenerateFile(OutFormat.EXCEL, new { FileName = "Report" });
}

This is going to be fine but sometimes I want to merge multiple Excel worksheets into one which is something like this:

public ActionResult GenerateExcel()
{
    Utils.XCore core = new Utils.XCore(...); // where ... are contructor params
    // ... other codes here ...
    var excel1 = core.GenerateFile(OutFormat.EXCEL, new { FileName = "rpt1" });
    var excel2 = core.GenerateFile(OutFormat.EXCEL, new { FileName = "rpt2" });
    var excel3 = core.GenerateFile(OutFormat.EXCEL, new { FileName = "rpt3" });

    var finalContent = combineFile(excel1, excel2, excel3);

    return new FileStreamResult(finalContent, "application/ms-excel")
       {
           FileDownloadName = "Report.xls"
       };
}

My problem now is I don't know how to get the content from FileStreamResult. Any ideas on how to do it? Even comments containing weblinks are pretty much appreciated. Thanks!

You need to reset the seek origin of the stream before using it to save/prompt user: http://stackoverflow.com/questions/1121703/asp-net-mvc-filestreamresult-not-working-as-intended — Papa, Nov 07 '14 at 03:56

score 2 · Accepted Answer · answered Nov 07 '14 at 06:09

If I correctly understand your question, you want to process/get the content from FileStreamResult. The class contains a property called FileStream which is a Stream object. Now, the stream object can now be saved as a file using the following modified code from this site:

private void streamToFile(Stream fileStream, string filePath)
{
    using (FileStream writeStream = new FileStream(filePath, 
                                    FileMode.Create, 
                                    FileAccess.Write))
    {
        int length = 1024;
        Byte[] buffer = new Byte[length];
        int bytesRead = fileStream.Read(buffer, 0, length);
        while (bytesRead > 0)
        {
            writeStream.Write(buffer, 0, bytesRead);
            bytesRead = fileStream.Read(buffer, 0, length);
        }
        fileStream.Close();
        writeStream.Close();
    }
}

and the following is how to use:

var excel1 = core.GenerateFile(OutFormat.EXCEL, new { FileName = "rpt1" });
string filePath = "C:\\yourFileName.xls"; // path of your newly saved file 
using (Stream reportStream = excel1.FileStream)
{
     streamToFile(reportStream, filePath);
}

How to get content from FileStreamResult

1 Answers1