MultipartFormDataを投稿しているときの問題c＃

Question

この質問を申し訳ありませんが、同じトピックについて既に多すぎる議論があることは知っています。すべてを試しましたが、正確な問題を特定できません。だから私は専門家からのインプットが必要です。

要件：非常に単純です.2つのテキストを文字列と1つのxmlファイルとして送信します。

以下のサンプルネットワークコールトレースは、ブラウザを使用して同じことを行っています。

C＃コードは同じacheiveします。

using (HttpClient http = new HttpClient()) 
     { 
      http.BaseAddress = new Uri("http://**.168.215.***"); 
      http.DefaultRequestHeaders.Add("User-Agent", 
       "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.110 Safari/537.36"); 
      http.DefaultRequestHeaders.Add("Content-Type", "multipart/form-data; boundary=----WebKitFormBoundarydsads"); 
      MultipartFormDataContent content = new MultipartFormDataContent(); 
      HttpContent datasource = new StringContent("test", Encoding.UTF8); 
      HttpContent feedtype = new StringContent("metadata-and-url", Encoding.UTF8); 
      string xmlText = File.ReadAllText(fi.FullName); 
      HttpContent data = new ByteArrayContent(File.ReadAllBytes(fi.FullName)); 
      content.Add(datasource, "datasource"); 
      content.Add(feedtype, "feedtype"); 
      content.Add(data, "data", "text.xml"); 

      var response = http.PostAsync("/xmlfeed", content).Result; 

     } 

レスポンスが "Bad Request 400"です。 これについてコメントしてください。

Answer 1

MultipartFormDataContentは境界を知らない。境界線はヘッダーにのみ設定します。

境界を含んでコンストラクタを使用しますが、ここで続きを読む： https://msdn.microsoft.com/en-us/library/hh138232(v=vs.118).aspx

Answer 2

を私が正常に長い時間のためHttpMultipartPostReuestを作成するために、このヘルパークラスを使用してきました。

using System; 
using System.Collections.Generic; 
using System.IO; 
using System.Net; 
using System.Text; 

namespace GeneralHelpers.Web 
{ 

    public class HttpMultipartPostReuest 
    { 

     private const string FileParamContentDisposition = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\";\r\nContent-Type: {2}\r\n\r\n"; 
     private const string GeneralParamContentDisposition = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; 
     private const string MultipartContent = "multipart/form-data; boundary="; 

     private readonly string _boundary; 
     private readonly byte[] _boundaryBytes; 
     private readonly string _contentType; 
     private readonly Encoding _encoding = Encoding.UTF8; 
     private readonly HttpWebRequest _request; 

     public string Boundary { get { return this._boundary; } } 

     public string ContentType { get { return this._contentType; } } 

     public HttpMultipartPostReuest(string url, Dictionary<string, object> postParameters) 
     { 
      this._boundary = HttpMultipartPostReuest.GenerateBoundary(); 
      this._boundaryBytes = Encoding.ASCII.GetBytes(string.Format("\r\n--{0}\r\n", this._boundary)); 
      this._contentType = HttpMultipartPostReuest.MultipartContent + this._boundary; 

      this._request = WebRequest.Create(url) as HttpWebRequest; 
      if (this._request == null) 
      { 
       throw new NullReferenceException("request is not a http request"); 
      } 

      byte[] formData = this.GetMultipartFormData(postParameters); 

      // Set up the request properties. 
      this._request.Method = WebRequestMethods.Http.Post; 
      this._request.ContentType = this._contentType; 
      this._request.ContentLength = formData.Length; 
      this._request.Credentials = System.Net.CredentialCache.DefaultCredentials; 

      // Send the form data to the request. 
      using (Stream requestStream = this._request.GetRequestStream()) 
      { 
       requestStream.Write(formData, 0, formData.Length); 
       requestStream.Close(); 
      } 
     } 

     private static string GenerateBoundary() 
     { 
      return string.Format("---------------------------{0}", DateTime.Now.Ticks.ToString("x")); 
     } 

     public WebResponse GetResponce() 
     { 
      return this._request.GetResponse(); 
     } 

     private byte[] GetMultipartFormData(Dictionary<string, object> postParameters) 
     { 
      using (Stream formDataStream = new MemoryStream()) 
      { 
       foreach (var param in postParameters) 
       { 
        //always wtiring boundary 
        formDataStream.Write(this._boundaryBytes, 0, this._boundaryBytes.Length); 

        FileParameter value = param.Value as FileParameter; 
        if (value != null) 
        { 
         FileParameter fileToUpload = value; 

         // Add just the first part of this param, since we will write the file data directly to the Stream 
         string header = string.Format(HttpMultipartPostReuest.FileParamContentDisposition, param.Key, fileToUpload.FileName ?? param.Key, 
          fileToUpload.ContentType); 

         formDataStream.Write(this._encoding.GetBytes(header), 0, this._encoding.GetByteCount(header)); 

         // Write the file data directly to the Stream, rather than serializing it to a string. 
         formDataStream.Write(fileToUpload.File, 0, fileToUpload.File.Length); 
        } 
        else 
        { 
         string postData = string.Format(HttpMultipartPostReuest.GeneralParamContentDisposition, param.Key, param.Value); 
         formDataStream.Write(this._encoding.GetBytes(postData), 0, this._encoding.GetByteCount(postData)); 
        } 
       } 

       // Add the end of the request. Start with a newline 
       string footer = "\r\n--" + this._boundary + "--\r\n"; 
       formDataStream.Write(this._encoding.GetBytes(footer), 0, this._encoding.GetByteCount(footer)); 

       // Dump the Stream into a byte[] 
       formDataStream.Position = 0; 
       byte[] formData = new byte[formDataStream.Length]; 
       formDataStream.Read(formData, 0, formData.Length); 
       formDataStream.Close(); 

       return formData; 
      } 
     } 

    } 

     public class FileParameter 
    { 
     private const string DefaultContentType = "application/octet-stream"; 

     private readonly string _contentType; 
     private readonly byte[] _file; 
     private readonly string _fileName; 

     public string ContentType { get { return this._contentType; } } 
     public byte[] File { get { return this._file; } } 
     public string FileName { get { return this._fileName; } } 

     private FileParameter() 
     { 
      this._contentType = FileParameter.DefaultContentType; 
     } 

     public FileParameter(byte[] file) : this(file, FileParameter.DefaultContentType) 
     { 
     } 

     public FileParameter(byte[] file, string filename) : this(file, filename, FileParameter.DefaultContentType) 
     { 
     } 

     public FileParameter(string path, string fileName) : this() 
     { 
      this._file = FileParameter.LoadFile(path); 
      this._fileName = fileName; 
     } 

     public FileParameter(string path, string fileName, string contentType) 
      : this() 
     { 
      this._file = FileParameter.LoadFile(path); 
      this._fileName = fileName; 
      this._contentType = contentType; 
     } 

     public FileParameter(byte[] file, string fileName, string contentType) 
     { 
      this._file = file; 
      this._fileName = fileName; 
      if (!string.IsNullOrWhiteSpace(contentType)) 
      { 
       this._contentType = contentType; 
      } 
      { 
       this._contentType = FileParameter.DefaultContentType; 
      } 
     } 

     private static byte[] LoadFile(string path) 
     { 
      byte[] data; 
      // Read file data 
      using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read)) 
      { 
       data = new byte[fs.Length]; 
       fs.Read(data, 0, data.Length); 
      } 

      return data; 
     } 

    } 

}