通过 API .net core 在浏览器中下载 mp3 文件

Question

试图通过我创建的 API 在浏览器中下载 mp3 文件。但不是接收 mp3 文件。我不断收到 JSON 格式的响应。我已经从中的答案中引用了，但我仍然无法下载 mp3 文件。有没有我忽略的错误，请帮忙？

这是我从UI

下载的方法

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 { }
}

这是我的 api 从服务器下载 mp3 的功能

 [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" }
          };
      }

这是我从浏览器和 Postman 得到的响应

{
    "Version": "2.0.0.0",
    "StatusCode": 200,
    "Message": "Status 200 OK",
    "Result":"��@� ... ... /// A lot of random symbol here
}

Answer 1

因为return值File的第一个参数是Stream的类型，所以需要传入memory

[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

我正在为此使用 Blazor。事实证明，Blazor APIReponse 中间件中有一个 API 响应包装器。我不得不将我的 API 放入异常中，这样当我访问它时它就不会变成 JSON。终于成功了。

下面是 Blazor 中的API响应包装器。

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);
                            }

通过 API .net core 在浏览器中下载 mp3 文件

Download mp3 file at browser through API .net core

rest

mp3

webclient

.net-core

asp.net-core-webapi