使用POST方式请求

string   url =   "http://localhost/BOOK/CH3/FirstServicecs.asmx/HelloWorld";     HttpWebRequest req   =   (HttpWebRequest)WebRequest.Create(url);     //POST方式请求     req.Method   =   "POST";     req.ContentType   =   "application/x-www-form-urlencoded";     string     strname=   System.Web.HttpUtility.UrlEncode("name");     strname   =   strname   +   "="   +   System.Web.HttpUtility.UrlEncode(textBox1.Text);     byte[]   payload;//将URL编码后的字符串转化为字节     payload   =   System.Text.Encoding.UTF8.GetBytes(strname);     req.ContentLength   =   payload.Length;     Stream   writer       =   req.GetRequestStream();     writer.Write(payload,   0,   payload.Length); writer.Close();     HttpWebResponse     response       =   (HttpWebResponse)req.GetResponse();     System.IO.Stream   s;     s   =   response.GetResponseStream();     XmlTextReader   reader   =new   XmlTextReader(s);     reader.MoveToContent();     label1.Text   =   reader.ReadInnerXml(); reader.Close(); using System;using System.Web;using System.Net;using System.IO;using System.Text;namespace SendMessage{

public bool SendMsg(MsgInfo msg){//create requesttry{WebRequest req = WebRequest.Create("http://your_post_url");

//set the request parameter req.Method = "POST";req.ContentType = "application/x-www-form-urlencoded";

//querystring '?msg=xxx&type=0'string strQuery = "msg=";strQuery += HttpUtility.UrlEncode(msg);strQuery += "&type=0";

string dataSend = strQuery;req.ContentLength = dataSend.Length;

byte [] buff = Encoding.UTF8.GetBytes(dataSend); Stream reqStream = req.GetRequestStream();reqStream.Write(buff, 0, buff.Length);reqStream.Close();

WebResponse rep = req.GetResponse();Stream repStream = rep.GetResponseStream();Encoding enc = Encoding.GetEncoding("utf-8");StreamReader sr = new StreamReader(repStream, enc);

Char[] read = new Char[256];sr.Read(read, 0, 256);

return true;}catch(NotSupportedException ns){return false; }}

}

string url = "http://localhost:21240/ChangeHair/Receive.aspx?aa=5";//发送到的页面的地址        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);

        //读取一个图片        FileStream fs = new FileStream(Server.MapPath("~/NET基础知识.doc"), System.IO.FileMode.Open, System.IO.FileAccess.Read);        byte[] filecontent = new byte[fs.Length];        fs.Read(filecontent, 0, filecontent.Length);        fs.Close();        fs.Dispose();

        //将图片转换成base64编码的流        string a = Convert.ToBase64String(filecontent);                 //读取base64编码流，发送        byte[] requestBytes = System.Text.Encoding.Default.GetBytes(a);

        req.Method = "POST";        req.ContentType = "application/x-www-form-urlencoded";        req.ContentLength = requestBytes.Length;        Stream requestStream = req.GetRequestStream();        requestStream.Write(requestBytes, 0, requestBytes.Length);        requestStream.Close();

        //接收返回参数，到string backstr        HttpWebResponse res = (HttpWebResponse)req.GetResponse();        StreamReader sr = new StreamReader(res.GetResponseStream(), System.Text.Encoding.Default);        string backstr = sr.ReadToEnd();        sr.Close();        res.Close();        //输出参数        Response.Write(backstr);