利用HttpWebRequest模拟表单提交

 using System;

 using System.Collections.Specialized;

 using System.IO;

 using System.Net;

 using System.Text;

 namespace Allyn.Common

 {

     public class HttpHelper

     {

         /// <summary>

         /// 获取指定路径数据

         /// </summary>

         /// <param name="requestUri">提交路径</param>

         /// <param name="cookie">Cookie容器对象</param>

         /// <returns>字符串结果</returns>

         public static string GetForm(string requestUri, CookieContainer cookie)

         {

             HttpWebRequest request = WebRequest.CreateHttp(requestUri);

             request.Method = "get";

             request.CookieContainer = cookie;

             request.ContentLength = ;

             WebResponse response = request.GetResponse();

             StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);

             return reader.ReadToEnd();

         }

         /// <summary>

         /// 默认表单提交

         /// </summary>

         /// <param name="requestUri">提交路径</param>

         /// <param name="postData">提交数据</param>

         /// <param name="cookie">Cookie容器对象</param>

         /// <returns>字符串结果</returns>

         public static string PostForm(string requestUri, NameValueCollection postData, CookieContainer cookie)

         {

             HttpWebRequest request = WebRequest.CreateHttp(requestUri);

             request.Method = "post";

             request.ContentType = "application/x-www-form-urlencoded";

             request.CookieContainer = cookie;

             StringBuilder stringBuilder = new StringBuilder();

             foreach (string key in postData.Keys)

             {

                 stringBuilder.AppendFormat("&{0}={1}", key, postData.Get(key));

             }

             byte[] buffer = Encoding.UTF8.GetBytes(stringBuilder.ToString().Trim('&'));

             Stream requestStream = request.GetRequestStream();

             requestStream.Write(buffer, , buffer.Length);

             requestStream.Close();

             WebResponse response = request.GetResponse();

             StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);

             return reader.ReadToEnd();

         }

         /// <summary>

         /// 多部件表单提交

         /// </summary>

         /// <param name="requestUri">提交路径</param>

         /// <param name="postData">提交数据.注:如果是文件路径,代表是文件.</param>

         /// <param name="cookie">Cookie容器对象</param>

         /// <returns>字符串结果</returns>

         public static string PostFormMultipart(string requestUri, NameValueCollection postData, CookieContainer cookie)

         {

             string boundary = string.Format("-----{0}", DateTime.Now.Ticks.ToString("x"));

             HttpWebRequest webrequest = WebRequest.CreateHttp(requestUri);

             webrequest.CookieContainer = cookie;

             webrequest.Timeout = ;

             webrequest.Method = "post";

             webrequest.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);

             Stream requestStream = webrequest.GetRequestStream();

             foreach (string key in postData.Keys)

             {

                 StringBuilder strBuilder = new StringBuilder();

                 strBuilder.AppendFormat("--{0}", boundary);

                 strBuilder.AppendFormat("\r\nContent-Disposition: form-data; name=\"{0}\"", key);

                 if (File.Exists(postData.Get(key)))

                 {

                     strBuilder.AppendFormat(";filename=\"{0}\"\r\nContent-Type: multipart/form-data\r\n\r\n", Path.GetFileName(postData.Get(key)));

                     byte[] buffer = Encoding.UTF8.GetBytes(strBuilder.ToString());

                     requestStream.Write(buffer, , buffer.Length);

                     //获取图片流

                     FileStream fileStream = new FileStream(postData.Get(key), FileMode.Open, FileAccess.Read);

                     BinaryReader binaryReader = new BinaryReader(fileStream);

                     byte[] fileBuffer = binaryReader.ReadBytes((int)fileStream.Length);

                     binaryReader.Close();

                     fileStream.Close();

                     requestStream.Write(fileBuffer, , fileBuffer.Length);

                 }

                 else

                 {

                     strBuilder.AppendFormat("\r\n\r\n{0}\r\n", postData.Get(key));

                     byte[] buff = Encoding.UTF8.GetBytes(strBuilder.ToString());

                     requestStream.Write(buff, , buff.Length);

                 }

             }

             byte[] boundaryBuffer = Encoding.UTF8.GetBytes(string.Format("\r\n--{0}\r\n", boundary));

             requestStream.Write(boundaryBuffer, , boundaryBuffer.Length);

             requestStream.Close();

             WebResponse response = webrequest.GetResponse();

             StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);

             return reader.ReadToEnd();

         }

     }

 }