CODEWITHSUNDEEP
asp.net-core-mvcumbracoclosedxmlfilecontentresult
Kyle White
Kyle White

Reputation: 1

My ASP.NET Core MVC controller method is supposed to return an Excel file with data, but it is empty

Here is my code:

public IActionResult DownloadMyFile(int Id)
{
    var fileData = // Service call to get data

    using (var workbook = new XLWorkbook())
    {
        var worksheet = workbook.AddWorksheet("data");

        var columnNames = fileData[0].GetType().GetProperties();
        var currentColumn = 1;

        foreach (var name in columnNames)
        {
            worksheet.Cell(1, currentColumn).Value = name.Name;
            currentColumn++;
        }

        worksheet.Cell(2, 1).InsertData(fileData);

        using (var stream = new MemoryStream())
        {
            workbook.SaveAs(stream);
            var content = stream.ToArray();

            return File(content,
                        "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                        "MyFile.xlsx");
        }
    }
}

I am using ClosedXML to put the data into an excel sheet. Then I save "worksheet" in a stream and convert it to a binary array and return that in a FileContentResult.

For context this lives in a controller in an Umbraco project

When I run my code and call this method, it returns an excel file with the correct name. But when I open the file, there is no data in it. I can't figure out why. When I debug my code, I can see that 'content' does have data in it. Any idea what's going on here?

I've tried changing the type to application/octect-stream which changed nothing.

I've also tried changing the return type to HttpResponseMethod but that has no effect either.

Upvotes: 0

Views: 365

Answers (1)

Robert Foster
Robert Foster

Reputation: 2316

Set the position in the stream to 0 prior to attempting to return it.

e.g.:

using (var stream = new MemoryStream())
{
    workbook.SaveAs(stream);
    stream.Seek(0, SeekOrigin.Begin);

    return File(stream,
                "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                "MyFile.xlsx");
}

Upvotes: 1

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