如何将文件从 REST API 发送到前端？

Question

我正在尝试编写一个服务，该服务从字符串（有效）构建一个 .ics 日历文件并将其发送到前端。前端通过 api 查询获取该文件。这就是我这边的样子：

var dataBytes = Encoding.ASCII.GetBytes(icsString);
var dataStream = new MemoryStream(dataBytes);

HttpResponseMessage httpResponseMessage = new HttpResponseMessage(HttpStatusCode.OK) { Content = new StreamContent(dataStream) };
httpResponseMessage.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment") { FileName = "file.ics" };
httpResponseMessage.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");

return httpResponseMessage;

正确吗？如果应该可以，那么前端如何获取JS中的数据呢？

Answer 1

您的代码看起来不错，您需要关闭fileStream并将responseStream位置设置为0。您可以参考我的代码。请确保该文件存在于路径中并且您正在处理异常

      //Copy the source file stream to MemoryStream and close the file stream
      MemoryStream responseStream = new MemoryStream();
      Stream fileStream = System.IO.File.Open(downloadFilePath, FileMode.Open);

      fileStream.CopyTo(responseStream);
      fileStream.Close();
      responseStream.Position = 0;

      HttpResponseMessage response = new HttpResponseMessage();
      response.StatusCode = HttpStatusCode.OK;

      //Write the memory stream to HttpResponseMessage content
      response.Content = new StreamContent(responseStream);
      string contentDisposition = string.Concat("attachment; filename=", fileName);
      response.Content.Headers.ContentDisposition = 
                    ContentDispositionHeaderValue.Parse(contentDisposition);
      return response;