C＃中的HttpClient多部分形式發佈＃

Question

我想要做一個多部分形式的帖子在C＃中使用HttpClient，我發現下面的代碼不起作用。

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); 
       } 
      } 
     } 
    } 
} 

我真的不知道爲什麼它不工作。我得到文件發佈到端點，但body（json）永遠不會到達那裏。難道我做錯了什麼？

服務器端代碼請求：

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

所以我看到的問題是，MultipartFormDataContent請求消息總是會設置內容類型的對「multipart/form-data」的請求。對json進行端點編碼並將其放入請求中只會看起來像模型活頁夾一樣是一個字符串。

的選項有：

• 有你的MVC操作方法得到的字符串和反序列化到你的對象
• 後模型的每個屬性作爲一個組成部分
• 創建一個自定義的模型綁定即會處理您的請求。
• 將操作分解爲兩個帖子，首先發送json元數據，另一個發送文件。來自服務器的響應應發送一些id或密鑰來關聯這兩個請求。

通過the RFC document閱讀和the MSDN documentation你可以做到這一點，如果你有MultipartContent替換MultipartFormDataContent。但我還沒有測試過。

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

這是如何使用MultipartFormDataContent與發佈的HTTPClient字符串和文件流的例子。 Content-Disposition和Content-Type需要爲每個HTTPContent指定：

這是我的例子。希望它有幫助：

 

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(); 
       } 
      } 
     }