用到的工具FireFox的Firebugs插件 打開網絡功能進行抓包 數據如下
可以得知POST的數據為：
__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=%2FwEPDwULLTE1MzYzODg2NzZkGAEFHl9fQ29udHJvbHNSZXF1aXJlUG9zdEJhY2tLZXlfXxYBBQtjaGtSZW1lbWJlcm1QYDyKKI9af4b67Mzq2xFaL9Bt&__EVENTVALIDATION=%2FwEWBQLWwpqPDQLyj%2FOQAgK3jsrkBALR55GJDgKC3IeGDE1m7t2mGlasoP1Hd9hLaFoI2G05&tbUserName=賬戶&tbPassword=密碼&btnLogin=%E7%99%BB++%E5%BD%95&txtReturnUrl=http%3A%2F%2Fhome.cnblogs.com%2F
在VS里畫登陸圖
查看別人的代碼 登錄代碼：
string postData =string.Format( "__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=/wEPDwULLTE1MzYzODg2NzZkGAEFHl9fQ29udHJvbHNSZXF1aXJlUG9zdEJhY2tLZXlfXxYBBQtjaGtSZW1lbWJlcm1QYDyKKI9af4b67Mzq2xFaL9Bt&__EVENTVALIDATION=/wEWBQLWwpqPDQLyj/OQAgK3jsrkBALR55GJDgKC3IeGDE1m7t2mGlasoP1Hd9hLaFoI2G05&tbUserName={0}&tbPassword={1}&btnLogin=登 錄&txtReturnUrl=http://home.cnblogs.com/",txtName.Text.Trim(),txtPwd.Text.Trim());
//這是cnblogs提交時的一些參數
ASCIIEncoding encoding = new ASCIIEncoding();
byte[] data = encoding.GetBytes(postData);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://passport.cnblogs.com/login.aspx");
request.Method = "Post";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
request.KeepAlive = true;
request.CookieContainer = container; //返回的cookie會附加在這個容器里面
//發送數據
Stream newStream = request.GetRequestStream();
newStream.Write(data, 0, data.Length);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
newStream = response.GetResponseStream();
StreamReader reader = new StreamReader(newStream, Encoding.UTF8);
string text = reader.ReadToEnd();
reader.Close();
newStream.Close();