string str_="";
string content=@"我传递的内容";
str_="我的URL？变量="+System.Web.HttpUtility.UrlEncode(content,System.Text.Encoding.GetEncoding ("gb2312") );

//请求
System.Net.HttpWebRequest myReq=(System.Net.HttpWebRequest)System.Net.WebRequest.Create(str_);
myReq.KeepAlive=false;
//回复
System.Net.HttpWebResponse myResp = (System.Net.HttpWebResponse)myReq.GetResponse();
string str=myResp.StatusDescription;
//读取回复
Stream answer=myResp.GetResponseStream ();
StreamReader ss=new StreamReader (answer);
string st=ss.ReadToEnd ();
Console.WriteLine (st);