c# - HttpRequestMessage/StreamContent，服务器端为空 Stream

Question

我想将流发布到 HTTP 服务器(由 OWINHost 托管)，请参见下面的代码片段。当我使用 StringContent 传输 String 时，它工作正常。但是，如果我想传输带有 StreamContent 的 MemoryStream，则服务器端接收到的流是空的(出于测试目的，我通过在客户端反序列化 MemoryStream 来验证 MemoryStream 是正确的)。我做错了什么？

客户端:

...
var request = new HttpRequestMessage(HttpMethod.Post, Configuration.ServiceBaseAddress);

// this works fine!
//request.Content = new StringContent("This is a test!!");

request.Content = new StreamContent(stream);
request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");

HttpResponseMessage response = await client.SendAsync(request);
...

服务器端:

public class Startup {
  public void Configuration(IAppBuilder app) {
    app.Run(async context => 
    {
      var stream = new MemoryStream();
      await context.Request.Body.CopyToAsync(stream);
      stream.Seek(0, SeekOrigin.Begin);

      // this works fine when I send StringContent
      //StreamReader reader = new StreamReader(stream);
      //String str = reader.ReadToEnd();

      // when I send StreamContent the stream object is empty
      IFormatter formatter = new BinaryFormatter();
      ServiceRequest requestTest = (ServiceRequest)formatter.Deserialize(stream);

      context.Response.ContentType = "text/plain";
      await context.Response.WriteAsync("Hello World!");
    });
  }
}

Answer 1

我忘了包括:

stream.Seek(0, SeekOrigin.Begin);

在客户端。