Return File in ASP.NET Core Web API

Return file in ASP.Net Core Web API

If this is ASP.net-Core then you are mixing web API versions. Have the action return a derived IActionResult because in your current code the framework is treating HttpResponseMessage as a model.

[Route("api/[controller]")]
public class DownloadController : Controller {
    //GET api/download/12345abc
    [HttpGet("{id}")]
    public async Task<IActionResult> Download(string id) {
        Stream stream = await {{__get_stream_based_on_id_here__}}

        if(stream == null)
            return NotFound(); // returns a NotFoundResult with Status404NotFound response.

        return File(stream, "application/octet-stream"); // returns a FileStreamResult
    }    
}

Note:

The framework will dispose of the stream used in this case when the response is completed. If a using statement is used, the stream will be disposed before the response has been sent and result in an exception or corrupt response.

ASP.NET Minimal API How to Return/Download Files from URL

You can use Results.File to return file to download from your Minimal APIs handler:

app.MapGet("/download", () =>
{
    var mimeType = "image/png";
    var path = @"path_to_png.png";
    return Results.File(path, contentType: mimeType);
});

Download file from dotnet Core Web API using POST in ASP.NET MVC 5 controller

Change GetPdf method to:

[Consumes("application/json")]
public IActionResult GetPDF([FromBody] ReportRequest request)
{
    //report generation logic
    return File(pdfMemoryStream.ToArray(), "application/pdf");
}

and use HttpClient instead of WebClient:

var client = new HttpClient();
string url = "https://localhost:44398/api/values/GetPdf";
var reportRequest = new ReportRequest()
{
    Id = 1,
    Type = "Billing"
};
var json = JsonConvert.SerializeObject(reportRequest);
var data = new StringContent(json, Encoding.UTF8, "application/json");
var response = await client.PostAsync(url, data);
response.EnsureSuccessStatusCode();
var bytes = await response.Content.ReadAsByteArrayAsync();

How to return file from ASP.net 5 web api

used IActionResult instead of HttpResponseMessage. And returned FileStreamResult, and got it working.

Got a new problem, the file is not the one I open with the stream from server. But will create a new question for that.

Continues : Return file from ASP.NET 5 Web API

Thanks

Return file from ASP.NET 5 Web API

Please see my answer in the other post: Return file as response

For reference, I think this fits your needs:

public FileResult TestDownload()
{
    HttpContext.Response.ContentType = "application/pdf";
    FileContentResult result = new FileContentResult(System.IO.File.ReadAllBytes("YOUR PATH TO PDF"), "application/pdf")
    {
        FileDownloadName = "test.pdf"
    };

    return result;                                
}

Return Download File in ASP.NET Core API from Axios Request

First of all, DownloadFile should be HttpGet instead of HttpPost.
Then your axios request should look like

axios({
  url: 'http://localhost:5000/api/products/download',
  method: 'GET',
  responseType: 'blob', // important
}).then((response) => {
  const url = window.URL.createObjectURL(new Blob([response.data]));
  const link = document.createElement('a');
  link.href = url;
  link.setAttribute('download', 'file.pdf');
  document.body.appendChild(link);
  link.click();
});

How to serve video file / stream from ASP Net Core 6 Minimal API

You can use the Results.Stream() method to return a stream from a minimal api.

string wwwroot = builder.Environment.WebRootPath;
...
app.MapGet("/video", () =>
{
    string filePath = Path.Combine(wwwroot, "test.mp4");
    return Results.Stream(new FileStream(filePath, FileMode.Open));
});

The stream parameter is disposed after the response is sent.

Results.Stream takes a few other optional parameters such as fileDownloadName, and contentType (which defaults to "application/octet-stream") that might be useful to you. Set enableRangeProcessing: true to enable range requests.

The above could easily be adapted to take a filename as a parameter, if you wish. You would need to consider validation (applies equally to the current code TBH). Tested and working for me.

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