download excel file from server to local machine in asp.net using web API and javascript

Question

this is my code: Html:

 <a class="castrol_button " data-bind="click: createExcelFile">download excel file</a>

In js part of my code I have this

   createExcelFile = function (data, event) {
   //call an API
 }

in my controller I Have this code :

   [HttpGet]
    public HttpResponseMessage CreatePaymentExcelFile(long Customerid)
      {
        try
        {
        // get data from DB to list which name is lst
        // using epplus dll for creating Excel file
     var file =new FileInfo(HttpContext.Current.Server.MapPath("~/DesktopModules/Castrolo2c/Resource/PaymentList.xlsx");

        using (ExcelPackage xlPackage = new ExcelPackage(file))
        {
            ExcelWorksheet worksheet = xlPackage.Workbook.Worksheets.Add("PaymentList");
            if (worksheet != null)
            {
                int row = 2;
                foreach( var i in res )
                {

                    worksheet.Cells[row, 1].Value = i.typename;
                    worksheet.Cells[row, 2].Value = i.pNO;
                    worksheet.Cells[row, 3].Value = i.Date;
                    worksheet.Cells[row, 4].Value = i.cashdate;
                    worksheet.Cells[row, 5].Value = i.Money;
                    worksheet.Cells[row, 6].Value = i.bedehkari;
                    worksheet.Cells[row, 7].Value = i.bestankari;
                    row++;
                }
                worksheet.Column(1).Width = 16;
                xlPackage.Workbook.Properties.Title = "patments";

                xlPackage.Workbook.Properties.Company = "Castrol";

                xlPackage.Save();

            return Request.CreateResponse(HttpStatusCode.OK);
        }
        catch (Exception e)
        {
            return Request.CreateResponse(HttpStatusCode.InternalServerError, "ERR"));
        } } 

every thing is fine and my excel file has been created in the folder in my server. but I want to copy the file to client machine. how can I do that ?

Answer 1

This should do the job

JS should be like:

createExcelFile = function (data, event) {
    e.preventDefault(); 
    window.location.href = '...'; //The Api Address
}

and the Api:

    [HttpGet]
    public HttpResponseMessage GetExcel()
    {
        using (var p = new OfficeOpenXml.ExcelPackage())
        {
            var ws = p.Workbook.Worksheets.Add("My WorkSheet");
            ws.Cells["A1"].Value = "A1";

            var stream = new System.IO.MemoryStream(p.GetAsByteArray());

            HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK)
            {
                Content = new StreamContent(stream)
            };
            result.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
            {
                FileName = "myworkbook.xlsx"
            };
            result.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");
            result.Content.Headers.ContentLength = stream.Length;
            return result;
        }
    }

Answer 2

You return http code so instead of this you should return

        Response.Clear();
        Response.AddHeader("", "");
        Response.Charset = System.Text.UTF8Encoding.UTF8.WebName;
        Response.AddHeader("content-disposition", "attachment;  filename="MyFile.xlsx");
        Response.ContentType = "application/text";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("utf-8");
        Response.BinaryWrite(xlPackage.GetAsByteArray());
        Response.End();