Asp.net web api 无法从https中的asp.net web api下载.apk文件

我的

Web API

代码如下，在http模式下工作，但不在https模式下工作。没有错误显示，只需给我一个http 204状态代码，反正无法下载apk文件，我的服务器是windows 2012。谢谢

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Web.Http;

namespace DownloadFileFromWebApi.Controllers
{
  [RoutePrefix("download")]
  public class DownloadController : ApiController
  {
    [Route("get_demo_file")]
    public HttpResponseMessage GetFileFromWebApi()
    {
      try
      {
        var FilePath = System.Web.Hosting.HostingEnvironment.MapPath(@"~/download/app.apk");
        var stream = new FileStream(FilePath, FileMode.Open);
        HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
        response.Content = new StreamContent(stream);
        response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
        response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { 
        FileName="app.apk"
        };
        return response;
      }
      catch
      {
        return new HttpResponseMessage(HttpStatusCode.NoContent);
      }
    }
  }
}