Download mp3 file at browser through API .net core - rest

Question

Was trying to download an mp3 file in a browser through the API that I created. But instead of receiving an mp3 file. I keep getting JSON format response. I had referred from answer in return-file-in-asp-net-core-web-api, but still, I can't download the mp3 file.
Is there any mistake that I've overlooked, please kindly help?
This is my downloading method from UI
void DownloadRecording(RecordingHistory voicehistory)
{
try
{
using (var client = new WebClient())
{
client.DownloadFile("https://2d489fd863a2.ngrok.io/api/download/" + voicehistory.RecordingId + ".mp3", voicehistory.RecordingId + ".mp3");
}
}
catch { }
}
This is my api function for downloading mp3 from server
[HttpGet("download/{recordingFile}")]
public async Task<IActionResult> DownloadVoiceRecording(string recordingFile)
{
string filePath = Directory.GetCurrentDirectory() + #"\audio\Processed\" + recordingFile;
var memory = new MemoryStream();
using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
await stream.CopyToAsync(memory);
}
memory.Position = 0;
var types = GetMimeTypes();
var ext = Path.GetExtension(filePath).ToLowerInvariant();
return File(filePath, types[ext], recordingFile);
}
private Dictionary<string, string> GetMimeTypes()
{
return new Dictionary<string, string>
{
{".mp3", "audio/mpeg"},
{".wav","audio/wav" }
};
}
This is the response I get from browser and Postman
{
"Version": "2.0.0.0",
"StatusCode": 200,
"Message": "Status 200 OK",
"Result":"��#� ... ... /// A lot of random symbol here
}

Answer 1

Because the first parameter of the return value File is a type of Stream, memory needs to be passed in.
[HttpGet("download/{recordingFile}")]
public async Task<IActionResult> DownloadVoiceRecording(string recordingFile)
{
string filePath = Directory.GetCurrentDirectory() + #"\audio\Processed\" + recordingFile;
var memory = new MemoryStream();
using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
await stream.CopyToAsync(memory);
}
memory.Position = 0;
var types = GetMimeTypes();
var ext = Path.GetExtension(filePath).ToLowerInvariant();
return File(memory, types[ext], recordingFile);
}

Answer 2

I'm using Blazor for this. It turns out that there was an API response wrapper in Blazor APIReponse middleware. I had to put my API into an exception so it won't turn into JSON when I access it. It works finally.
Below is the APIReponse wrapper in Blazor.
var formattedRequest = await FormatRequest(request);
var originalBodyStream = httpContext.Response.Body;
using (var responseBody = new MemoryStream())
{
try
{
string responseBodyContent = null;
var response = httpContext.Response;
if (new string[] { "/api/localization", "/api/data", "/api/externalauth", "/api/download" }.Any(e => request.Path.StartsWithSegments(new PathString(e.ToLower()))))
await _next.Invoke(httpContext);
else
{
response.Body = responseBody;
await _next.Invoke(httpContext);
//wrap response in ApiResponse
if (httpContext.Response.StatusCode == Status200OK)
{
responseBodyContent = await FormatResponse(response);
await HandleSuccessRequestAsync(httpContext, responseBodyContent, Status200OK);
}
else
await HandleNotSuccessRequestAsync(httpContext, httpContext.Response.StatusCode);
}