C# 使用HttpWebRequest通过PHP接口 上传文件

  1  public string UploadFile(string uploadfile, string url, NameValueCollection querystring, CookieContainer cookies, string fileFormName = "file", string contenttype = "multipart/form-data")
  2         {
  3             if ((fileFormName == null) ||
  4                     (fileFormName.Length == 0))
  5             {
  6                 fileFormName = "file";
  7             }
  8 
  9             if ((contenttype == null) ||
 10                 (contenttype.Length == 0))
 11             {
 12                 contenttype = "application/octet-stream";
 13             }
 14             Uri uri = new Uri(url);
 15             string boundary = "----------" + DateTime.Now.Ticks.ToString("x");
 16             HttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create(uri);
 17             webrequest.CookieContainer = cookies;
 18             webrequest.ContentType = "multipart/form-data; boundary=" + boundary;
 19             webrequest.Method = "POST";
 20             StringBuilder sb = new StringBuilder();
 21             sb.Append("--");
 22             sb.Append(boundary);
 23             sb.Append("\r\n");
 24             sb.Append("Content-Disposition: form-data; name=\"");
 25             sb.Append(fileFormName);
 26             sb.Append("\"; filename=\"");
 27             sb.Append(uploadfile);
 28             sb.Append("\"");
 29             sb.Append("\r\n");
 30             sb.Append("Content-Type: ");
 31             sb.Append(contenttype);
 32             sb.Append("\r\n");
 33             sb.Append("\r\n");
 34 
 35             string postHeader = sb.ToString();
 36             byte[] postHeaderBytes = Encoding.UTF8.GetBytes(postHeader);
 37             byte[] boundaryBytes = Encoding.ASCII.GetBytes("--" + boundary + "\r\n");
 38             byte[] br = Encoding.ASCII.GetBytes("\r\n");
 39             FileStream fileStream = new FileStream(uploadfile, FileMode.Open, FileAccess.Read);
 40             long length = postHeaderBytes.Length + fileStream.Length + br.Length;
 41             if (querystring != null)
 42             {
 43 
 44                 StringBuilder sub = new StringBuilder();
 45                 foreach (string key in querystring.Keys)
 46                 {
 47                     sub.Append("--");
 48                     sub.Append(boundary);
 49                     sub.Append("\r\n");
 50                     sub.Append("Content-Disposition: form-data; name=\"");
 51                     sub.Append(key);
 52                     sub.Append("\"");
 53                     sub.Append("\r\n");
 54                     sub.Append("\r\n");
 55                     sub.Append(querystring[key]);
 56                     sub.Append("\r\n");
 57                     byte[] formitembytes = Encoding.UTF8.GetBytes(sub.ToString());
 58                     length += formitembytes.Length;
 59                 }
 60             }
 61             length += boundaryBytes.Length;
 62             webrequest.ContentLength = length;
 63             Stream requestStream = webrequest.GetRequestStream();
 64             // Write out our post header 
 65             requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);
 66 
 67             // Write out the file contents 
 68             byte[] buffer = new Byte[checked((uint)Math.Min(4096, (int)fileStream.Length))];
 69             int bytesRead = 0;
 70             while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
 71                 requestStream.Write(buffer, 0, bytesRead);
 72             requestStream.Write(br, 0, br.Length);
 73             if (querystring != null)
 74             {
 75                 StringBuilder sub = new StringBuilder();
 76                 foreach (string key in querystring.Keys)
 77                 {
 78                     sub.Append("--");
 79                     sub.Append(boundary);
 80                     sub.Append("\r\n");
 81                     sub.Append("Content-Disposition: form-data; name=\"");
 82                     sub.Append(key);
 83                     sub.Append("\"");
 84                     sub.Append("\r\n");
 85                     sub.Append("\r\n");
 86                     sub.Append(querystring[key]);
 87                     sub.Append("\r\n");
 88                     byte[] formitembytes = Encoding.UTF8.GetBytes(sub.ToString());
 89                     requestStream.Write(formitembytes, 0, formitembytes.Length);
 90                 }
 91             }
 92             // Write out the trailing boundary   
 93             requestStream.Write(boundaryBytes, 0, boundaryBytes.Length);
 94             webrequest.Timeout = 1000000;
 95 
 96             WebResponse responce = webrequest.GetResponse();
 97 
 98             Stream s = responce.GetResponseStream();
 99 
100             StreamReader sr = new StreamReader(s);
101 
102             string str = sr.ReadToEnd();
103 
104 
105             fileStream.Close();
106 
107             requestStream.Close();
108 
109             sr.Close();
110 
111             s.Close();
112 
113             responce.Close();
114 
115             return str;
116 
117         }