Asp.net WebApi Aspose.Cells - export and download excel

C#

    [Route("xls")]
    [HttpPost] // can use Get, but Post seems to be recommended
    public HttpResponseMessage Export()
    {
        var response = new HttpResponseMessage();

        try
        {
            // Create workbook
            var wb = new Workbook();

            /* ** fill in workbook / worksheet content ** */

            // save workbook to MemoryStream
            var stream = new MemoryStream();
            wb.Save(stream, SaveFormat.Xlsx);
            stream.Position = 0;    // important!

            // add stream to response
            response.Content = new StreamContent(stream);

            // set Headers
            response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue(dispositionType: "attachment"); // or "inline"
            response.Content.Headers.ContentDisposition.FileName = wb.FileName; // or other means of getting filename
            response.Content.Headers.ContentType = new MediaTypeHeaderValue(mediaType: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            response.Content.Headers.ContentLength = stream.Length;

            // set the success code
            response.StatusCode = HttpStatusCode.OK;
        }
        catch(Exception ex)
        {
            response.StatusCode = HttpStatusCode.InternalServerError;
            response.Content = null; // just in case
            response.ReasonPhrase = ex.Message;
        }

        return response;
    }

If you have CORS enabled, you may need to allow the Content-Disposition header:

    public static void Register(HttpConfiguration config)
    {
        var cors = new EnableCorsAttribute(origins: "*", headers: "*", methods: "*");
        cors.ExposedHeaders.Add(item: "Content-Disposition");
        config.EnableCors(cors);

        /* The rest of WebAPI configuration */
    }

For the Javascript side -- the answer here may help. (Note: make sure you set the method to POST, or change my example to GET.)

In ASP.NET, you can send your XLS or XLSX file to browser via the following code.

C#

//Save file and send to client browser using selected format
if (yourFileFormat == "XLS")
{
      workbook.Save(HttpContext.Current.Response, "output.xls", ContentDisposition.Attachment, new XlsSaveOptions(SaveFormat.Excel97To2003));

}
else
{
      workbook.Save(HttpContext.Current.Response, "output.xlsx", ContentDisposition.Attachment, new OoxmlSaveOptions(SaveFormat.Xlsx));
}

HttpContext.Current.Response.End();

The above code will send XLS file to browser. If you change this line

if (yourFileFormat == "XLS")

to something like

if (yourFileFormat == "XLSX")

then it will send XLSX file to browser. Please download the ASP.NET Web Application Project from the following link to see the above code running.

Project Link:

http://www.aspose.com/community/forums/293730/postattachment.aspx

Please do not use Workbook.SaveToStream() method to get memory stream object. Please check the following code, how you can get memory stream object of different formats like XLS, XLSX etc.

//Create workbook object
Workbook wb = new Workbook("source.xlsx");

//This is how to save Workbook to XLS format
MemoryStream ms1 = new MemoryStream();
wb.Save(ms1, SaveFormat.Excel97To2003);

//Just to check if memory stream is good and contains XLS bytes
byte[] b1 = ms1.ToArray();
File.WriteAllBytes("output.xls", b1);

//This is how to save Workbook to XLSX format
MemoryStream ms2 = new MemoryStream();
wb.Save(ms2, SaveFormat.Xlsx);

//Just to check if memory stream is good and contains XLSX bytes
byte[] b2 = ms2.ToArray();
File.WriteAllBytes("output.xlsx", b2);

Note: I am working as Developer Evangelist at Aspose

Using .net so slightly adjusted from Andews version using the File action result.

[HttpGet("download")]
    public async Task<IActionResult> DownloadSystem()
    {
        var workbook = new Workbook();
        var fileName = $"Report.xlsx";
        var cd = new System.Net.Mime.ContentDisposition
        {
            FileName = fileName,
            Inline = false, 
        };
        Response.Headers.Add("Content-Disposition", cd.ToString());
        var stream = new MemoryStream();
        workbook.Save(stream, SaveFormat.Xlsx);
        stream.Position = 0;
        return File(stream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", fileName);
    }