利用WebRequest来实现模拟浏览器通过Post方式向服务器提交数据

   //通过Post发送的数据
   string payload=”chkbook=book&keyword=管理”;
   WebRequest req = WebRequest.Create(”http://localhost/pceo/Search.aspx”);
   req.Method = “POST”;
   req.ContentType = “application/x-www-form-urlencoded”;
   StringBuilder UrlEncoded = new StringBuilder();
   Char[] reserved = {’?', ‘=’, ‘&’};
   byte[] SomeBytes = null;
   if (payload != null)
   {
   int i=0, j;
   while(i<payload.Length)
   {
   j=payload.IndexOfAny(reserved, i);
   if (j==-1)
   {
   UrlEncoded.Append(HttpUtility.UrlEncode(payload.Substring(i, payload.Length-i),System.Text .Encoding .GetEncoding (”gb2312″)));
   break;
   }
   UrlEncoded.Append(HttpUtility.UrlEncode(payload.Substring(i, j-i),System.Text .Encoding .GetEncoding (”gb2312″)));
   UrlEncoded.Append(payload.Substring(j,1));
   i = j+1;
   }
   SomeBytes = Encoding.Default.GetBytes(UrlEncoded.ToString());
   req.ContentLength = SomeBytes.Length;
   Stream newStream = req.GetRequestStream();
   newStream.Write(SomeBytes, 0, SomeBytes.Length);
   newStream.Close();
   }
   else
   {
   req.ContentLength = 0;
   }
   try
   {
   WebResponse result = req.GetResponse();
   Stream ReceiveStream = result.GetResponseStream();
  
   Byte[] read = new Byte[512];
   int bytes = ReceiveStream.Read(read, 0, 512);
  
   txtHTML.InnerHtml = “”;
   while (bytes > 0)
   {
  
   // 注意：
   // 下面假定响应使用 UTF-8 作为编码方式。
   // 如果内容以 ANSI 代码页形式（例如，932）发送，则使用类似下面的语句：
   // Encoding encode = System.Text.Encoding.GetEncoding(”shift-jis”);
   Encoding encode = System.Text.Encoding.GetEncoding(”gb2312″);
   txtHTML.InnerHtml = txtHTML.InnerHtml + encode.GetString(read, 0, bytes);
   bytes = ReceiveStream.Read(read, 0, 512);
   }
   }
   catch(Exception)
   {
   txtHTML.InnerHtml = “检索页时出错”;
   }