C＃中的HttpClient多部分形式发布＃

Question

我想要做一个多部分形式的帖子在C＃中使用HttpClient，我发现下面的代码不起作用。

重要：

var jsonToSend = JsonConvert.SerializeObject(json, Formatting.None, new IsoDateTimeConverter()); 
var multipart = new MultipartFormDataContent(); 
var body = new StringContent(jsonToSend, Encoding.UTF8, "application/json"); 

multipart.Add(body); 
multipart.Add(new ByteArrayContent(File.ReadAllBytes("test.txt")), "test", "test.txt"); 

var httpClient = new HttpClient(); 
var response = httpClient.PostAsync(new Uri("http://localhost:55530"), multipart).Result; 

完整程序：

namespace CourierMvc.Worker 
{ 
    class Program 
    { 
     static void Main(string[] args) 
     { 
      while (true) 
      { 
       Console.WriteLine("Hit any key to make request."); 
       Console.ReadKey(); 

       try 
       { 
        var request = new RestRequest(Method.POST) 
        { 
         Resource = "http://localhost:55530" 
        }; 

        var json = new CourierMessage 
        { 
         Id = Guid.NewGuid().ToString(), 
         Key = "awesome", 
         From = "khalid@home.com", 
         To = new[] { "me@test.com", "you@test.com" }, 
         Subject = "test", 
         Body = "body", 
         Processed = DateTimeOffset.UtcNow, 
         Received = DateTime.Now, 
         Created = DateTime.Now, 
         Sent = DateTime.Now, 
         Links = new[] { new Anchor { Link = "http://google.com" }, new Anchor { Link = "http://yahoo.com" } } 
        }; 

        var jsonToSend = JsonConvert.SerializeObject(json, Formatting.None, new IsoDateTimeConverter()); 
        var multipart = new MultipartFormDataContent(); 
        var body = new StringContent(jsonToSend, Encoding.UTF8, "application/json"); 

        multipart.Add(body); 
        multipart.Add(new ByteArrayContent(File.ReadAllBytes("test.txt")), "test", "test.txt"); 

        var httpClient = new HttpClient(); 
        var response = httpClient.PostAsync(new Uri("http://localhost:55530"), multipart).Result; 

       } 
       catch (Exception e) 
       { 
        Console.WriteLine(e); 
       } 
      } 
     } 
    } 
} 

我真的不知道为什么它不工作。我得到文件发布到端点，但body（json）永远不会到达那里。难道我做错了什么？

服务器端代码请求：

namespace CourierMvc.Controllers 
{ 
    public class HomeController : Controller 
    { 
     // 
     // GET: /Home/ 

     public ActionResult Index() 
     { 
      return Content("Home#Index"); 
     } 


     [ValidateInput(false)] 
     public ActionResult Create(CourierMessage input) 
     { 
      var files = Request.Files; 

      return Content("OK"); 
     } 

    } 
} 

路由配置：

public static void RegisterRoutes(RouteCollection routes) 
{ 
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); 

    routes.MapRoute(
     name: "Default", 
     url: "{controller}/{action}/{id}", 
     defaults: new { controller = "Home", action = "Create", id = UrlParameter.Optional } 
    ); 

} 

Answer 1

所以我看到的问题是，MultipartFormDataContent请求消息总是会设置内容类型的对“multipart/form-data”的请求。对json进行端点编码并将其放入请求中只会看起来像模型活页夹一样是一个字符串。

的选项有：

• 有你的MVC操作方法得到的字符串和反序列化到你的对象
• 后模型的每个属性作为一个组成部分
• 创建一个自定义的模型绑定即会处理您的请求。
• 将操作分解为两个帖子，首先发送json元数据，另一个发送文件。来自服务器的响应应发送一些id或密钥来关联这两个请求。

通过the RFC document阅读和the MSDN documentation你可以做到这一点，如果你有MultipartContent替换MultipartFormDataContent。但我还没有测试过。

Answer 2

public class CourierMessage 
{ 
    public string Id { get; set; } 
    public string Key { get; set; } 
    public string From { get; set; } 
    public string Subject { get; set; } 
    public string Body { get; set; } 
    public DateTimeOffset Processed { get; set; } 
    public DateTime Received { get; set; } 
    public DateTime Created { get; set; } 
    public DateTime Sent { get; set; } 
    public HttpPostedFileBase File { get; set; } 
} 




while (true) 
{ 
    Console.WriteLine("Hit any key to make request."); 
    Console.ReadKey(); 

    using (var client = new HttpClient()) 
    { 
     using (var multipartFormDataContent = new MultipartFormDataContent()) 
     { 
      var values = new[] 
      { 
       new KeyValuePair<string, string>("Id", Guid.NewGuid().ToString()), 
       new KeyValuePair<string, string>("Key", "awesome"), 
       new KeyValuePair<string, string>("From", "khalid@home.com") 
       //other values 
      }; 

      foreach (var keyValuePair in values) 
      { 
       multipartFormDataContent.Add(new StringContent(keyValuePair.Value), 
        String.Format("\"{0}\"", keyValuePair.Key)); 
      } 

      multipartFormDataContent.Add(new ByteArrayContent(File.ReadAllBytes("test.txt")), 
       '"' + "File" + '"', 
       '"' + "test.txt" + '"'); 

      var requestUri = "http://localhost:5949"; 
      var result = client.PostAsync(requestUri, multipartFormDataContent).Result; 
     } 
    } 
} 

Answer 3

这是如何使用MultipartFormDataContent与发布的HTTPClient字符串和文件流的例子。 Content-Disposition和Content-Type需要为每个HTTPContent指定：

这是我的例子。希望它有帮助：

 

private static void Upload() 
     { 

      using (var client = new HttpClient()) 
      { 
       client.DefaultRequestHeaders.Add("User-Agent", "CBS Brightcove API Service"); 

       using (var content = new MultipartFormDataContent()) 
       { 
        var path = @"C:\B2BAssetRoot\files\596086\596086.1.mp4"; 

        string assetName = Path.GetFileName(path); 

        var request = new HTTPBrightCoveRequest() 
         { 
          Method = "create_video", 
          Parameters = new Params() 
           { 
            CreateMultipleRenditions = "true", 
            EncodeTo = EncodeTo.Mp4.ToString().ToUpper(), 
            Token = "x8sLalfXacgn-4CzhTBm7uaCxVAPjvKqTf1oXpwLVYYoCkejZUsYtg..", 
            Video = new Video() 
             { 
              Name = assetName, 
              ReferenceId = Guid.NewGuid().ToString(), 
              ShortDescription = assetName 
             } 
           } 
         }; 

        //Content-Disposition: form-data; name="json" 
        var stringContent = new StringContent(JsonConvert.SerializeObject(request)); 
        stringContent.Headers.Add("Content-Disposition", "form-data; name=\"json\""); 
        content.Add(stringContent, "json"); 


        FileStream fs = File.OpenRead(path); 

        var streamContent = new StreamContent(fs); 
        streamContent.Headers.Add("Content-Type", "application/octet-stream"); 
        streamContent.Headers.Add("Content-Disposition", "form-data; name=\"file\"; filename=\"" + Path.GetFileName(path) + "\""); 
        content.Add(streamContent, "file", Path.GetFileName(path)); 

        //content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment"); 



        Task message = client.PostAsync("http://api.brightcove.com/services/post", content); 

        var input = message.Result.Content.ReadAsStringAsync(); 
        Console.WriteLine(input.Result); 
        Console.Read(); 
       } 
      } 
     }