does HTTPResponse Response exist in .NET Core 3.1

Question

I'm trying to export data from an asp.net core webapplication (Blazor) to an excel file. Excel file has to show up in the browser, to be downloaded by the user.

Per all the examples I use Response:

using System;
using System.IO;
using ClosedXML.Excel;
using System.Data;
using System.Web;
using Microsoft.AspNetCore.Http;

namespace Sxxx
{
    public class Exporter
    {
        public void Export()
        {
            using (IXLWorkbook wb = new XLWorkbook())
            {
                IXLWorksheet ws = wb.Worksheets.Add("Sample Sheet");

                ws.Cell(1, 1).Value = "Hello World!";

                Response.Clear();
                Response.Buffer = true;
                Response.Charset = "";
                Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                Response.AddHeader("content-disposition", "attachment;filename=SqlExport.xlsx");
                using (MemoryStream MyMemoryStream = new MemoryStream())
                {
                    wb.SaveAs(MyMemoryStream);
                    MyMemoryStream.WriteTo(Response.OutputStream);
                    Response.Flush();
                    Response.End();
                }
            }
                       
        }
    }

However Response is not recognized. The missing assembly that VS 2019 shows is "Ubiety.Dns.Core", but that doesn't seem right.

In docs.microsoft.com HTTPresponse only shows up as part of Framework 4.8, so my question: can I use Response here or do I need something else for a Core 3.1 project?

Thanks in advance

user_2476248 · Answer

I did create a Controller, as suggested by Marco and Noah, many thanks. I did learn a lot... Response inherits from ControllerBase. Most of the examples on the web are for .Net Framework 4.8, so it was a bit of a puzzle to do it for core 3.1 but here it is. Suggestions to improve are more then welcome.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.IO;
using ClosedXML.Excel;


namespace Sxxx.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class DownLoadController : ControllerBase
    {
        private readonly IWebHostEnvironment environment;
        public DownLoadController(IWebHostEnvironment environment)
        {
            this.environment = environment;
        }

        [HttpGet("[action]")]
        public async Task DownLoadFile()    
        {
            IXLWorkbook wb = new XLWorkbook();
            IXLWorksheet ws = wb.Worksheets.Add("Sample Sheet");
            ws.Cell(1, 1).Value = "Hello World!";
            MemoryStream ms = new MemoryStream();
            wb.SaveAs(ms);
            byte[] result = ms.ToArray();

            Response.Clear();
            Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
            Response.Headers.Add("Content-Disposition", "attachment; filename=somefile.xlsx");
            
            await Response.Body.WriteAsync(result);
            await Response.StartAsync();
                  
        }
    }
}

does HTTPResponse Response exist in .NET Core 3.1

1 Answers