C# post提交

WebForm

前台

<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
            <asp:Label ID="Label1" runat="server" Text="Label">返回值</asp:Label>

后台

 protected void Button1_Click(object sender, EventArgs e)
        {
　　　　　　　　//1
            //string url = "地址和参数";
            //try
            //{
            //    HttpWebRequest req = WebRequest.Create(url) as HttpWebRequest;
            //    req.ContentType = "application/x-www-form-urlencoded";
            //    req.Accept = "*/*";
            //    req.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)";
            //    req.Timeout = 10000;//10秒连接不成功就中断 
            //    req.Method = "post";
            //    HttpWebResponse response = req.GetResponse() as HttpWebResponse;
            //    StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.Default);
            //    this.Label1.Text = sr.ReadToEnd();
            //}
            //catch (WebException ex)
            //{
            //    Console.WriteLine(ex.ToString());
            //}
            //Console.WriteLine(url);

　　　　　　　　//2
            string postData = "参数"; // 要发放的数据 
            string postUrl = "地址";
            byte[] byteArray = Encoding.Default.GetBytes(postData); //转化
            HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(new Uri(postUrl));
            webReq.Method = "POST";
            webReq.ContentType = "application/x-www-form-urlencoded";
            webReq.ContentLength = byteArray.Length;
            Stream newStream = webReq.GetRequestStream();
            newStream.Write(byteArray, 0, byteArray.Length);//写入参数
            newStream.Close();
            HttpWebResponse response = (HttpWebResponse)webReq.GetResponse();
            StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.Default);
            this.Label1.Text = sr.ReadToEnd();
            sr.Close();
            response.Close();
            newStream.Close();

　　　　　　　　//3
            //byte[] postData = Encoding.UTF8.GetBytes("参数");//这里即为传递的参数，可以用工具抓包分析，也可以自己分析，主要是form里面每一个name都要加进来  编码
            //string url = "地址";//地址  
            //WebClient webClient = new WebClient();
            //webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");//采取POST方式必须加的header，如果改为GET方式的话就去掉这句话即可  
            //byte[] responseData = webClient.UploadData(url, "POST", postData);//得到返回字符流  
            //string srcString = Encoding.UTF8.GetString(responseData);//解码  
            //this.Label1.Text = srcString;

　　　　　　　　//4
            //string postData = "参数"; // 要发放的数据 
            //string postUrl = "地址";
            //HttpWebRequest request = (HttpWebRequest)WebRequest.Create(postUrl);
            //request.Method = "POST";
            //request.ContentType = "application/x-www-form-urlencoded";
            //request.ContentLength = Encoding.UTF8.GetByteCount(postData);
            ////request.CookieContainer = cookie;//获取记录（储存在用户本地终端上的数据）
            //Stream myRequestStream = request.GetRequestStream();
            //StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312"));
            //myStreamWriter.Write(postData);
            //myStreamWriter.Close();
            //HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            ////response.Cookies = cookie.GetCookies(response.ResponseUri);//获取记录（储存在用户本地终端上的数据）
            //Stream myResponseStream = response.GetResponseStream();
            //StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
            //string retString = myStreamReader.ReadToEnd();
            //this.Label1.Text = retString;
            //myStreamReader.Close();
            //myResponseStream.Close();
        }

这些都是到处总结出来的