C#三种模拟自动登录和提交POST信息的实现方法

页自动登录（提交Post内容）的用途很多，如验证身份、程序升级、网络投票等，以下是用C#实现的方法。
   网页自动登录和提交POST信息的核心就是分析网页的源代码（HTML），在C#中，可以用来提取网页HTML的组件比较多，常用的用WebBrowser、WebClient、HttpWebRequest这三个。以下就分别用这三种方法来实现：
   1、WebBrowser是个"迷你"浏览器，其特点是Post时不用关心Cookie、内置JS等问题
   WebBrowser是VS2005新提供的组件（其实就是封装了IE接口），实现POST功能一般在webBrowser的DocumentCompleted中分析HtmlDocument 来实现，代码如下：
         HtmlElement ClickBtn =null;
          if (e.Url.ToString().ToLower().IndexOf("xxx.htm") > 0) //登陆页面
         {
            HtmlDocument doc = webBrowser1.Document;
            for (int i = 0; i < doc.All.Count ; i++)
            {
                   if (doc.All.TagName.ToUpper().Equals("INPUT"))
                   {
                     switch (doc.All.Name)
                     {
                        case "userCtl":
                               doc.All.InnerText = "user01";
                               break;
                        case "passCt1":
                               doc.All.InnerText = "mypass";
                               break;
                        case "B1":
                               ClickBtn = doc.All; //提交按钮
                               break;
                     }
                   }
            }
            ClickBtn.InvokeMember("Click"); //执行按扭操作
         }
   2、WebClient封装了HTTP的一些类，操作简单，相较于webBrowser，特点是可以自设代理，缺点是对COOKIE的控制
   WebClient的运行全在后台，并且提供了异步操作的能力，这样很方便并发多个任务，然后等待结果的返回，再逐个处理。多任务异步调用的代码如下：
** void StartLoop(int ProxyNum)
       {
         WebClient [] wcArray = new WebClient[ProxyNum]; //初始化
             for (int idArray = 0; idArray< ProxyNum;idArray++)
         {
                wcArray[idArray] = new WebClient();
            wcArray[idArray].OpenReadCompleted += new OpenReadCompletedEventHandler(Pic_OpenReadCompleted2);
            wcArray[idArray].UploadDataCompleted += new UploadDataCompletedEventHandler(Pic_UploadDataCompleted2);
            try
            {
                  ......
                   wcArray[idArray].Proxy = new WebProxy(proxy[1], port);
               wcArray[idArray].OpenReadAsync(new Uri("http://xxxx.com.cn/tp.asp?Id=129")); //打开WEB;
                   proxy = null;
            }
            catch
            {
            }
         }
       }
       ** void Pic_OpenReadCompleted2(object sender, OpenReadCompletedEventArgs e)
       {
            if (e.Error == null)
            {
                        string textData = new StreamReader(e.Result, Encoding.Default).ReadToEnd(); //取返回信息
                        .....
                           String cookie = ((WebClient)sender).ResponseHeaders["Set-Cookie"];
                            ((WebClient)sender).Headers.Add("Content-Type", "application/x-www-form-urlencoded");
                        ((WebClient)sender).Headers.Add("Accept-Language", "zh-cn");
                        ((WebClient)sender).Headers.Add("Cookie", cookie);
                        string postData = "......"
                        byte[] byteArray = Encoding.UTF8.GetBytes(postData); // 转化成二进制数组
                        ((WebClient)sender).UploadDataAsync(new Uri("http://xxxxxxy.com.cn/tp.asp?Id=129"), "POST", byteArray);
            }
      }
       ** void Pic_UploadDataCompleted2(object sender, UploadDataCompletedEventArgs e)
       {
                if (e.Error == null)
            {
                   string returnMessage = Encoding.Default.GetString(e.Result);
                  ......
                }
   }
   3、HttpWebRequest较为低层，能实现的功能较多，Cookie操作也很简单
       ** bool PostWebRequest()       
       {
               CookieContainer cc = new CookieContainer();
                   string pos tData = "user=" + strUser + "&pass=" + strPsd;
                   byte[] byteArray = Encoding.UTF8.GetBytes(postData); // 转化
                   HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(new Uri("http://www.xxxx.com/chk.asp"));
                   webRequest2.CookieContainer = cc;
                   webRequest2.Method = "POST";
                   webRequest2.C;
                   webRequest2.ContentLength = byteArray.Length;
                   Stream newStream = webRequest2.GetRequestStream();
                   // Send the data.
                   newStream.Write(byteArray, 0, byteArray.Length); //写入参数
                   newStream.Close();
                   HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();
                   StreamReader sr2=new StreamReader(response2.GetResponseStream(), Encoding.Default);
                   string text2 = sr2.ReadToEnd();
               ......
      }               
             HttpWebRequest同样提供了异步操作.