C#網頁自動登入和提交

網頁自動登入（提交Post內容）的用途很多，如驗證身份、程式升級、網路投票等，以下是用C#實現的方法。        網頁自動登入和提交POST資訊的核心就是分析網頁的原始碼（HTML），在C#中，可以用來提取網頁HTML的組件比較多，常用的用WebBrowser、WebClient、HttpWebRequest這三個。以下就分別用這三種方法來實現：      1、WebBrowser是個"迷你"瀏覽器，其特點是Post時不用關心Cookie、內建JS等問題       WebBrowser是VS2005新提供的組件（其實就是封裝了IE介面），實現POST功能一般在webBrowser的DocumentCompleted中分析HtmlDocument 來實現，代碼如下：

HtmlElement ClickBtn =null;                        if (e.Url.ToString().ToLower().IndexOf("xxx.htm") > 0)   //登陸頁面             {                             HtmlDocument doc = webBrowser1.Document;                             for (int i = 0; i < doc.All.Count ; i++)                             {                                 if (doc.All[i].TagName.ToUpper().Equals("INPUT"))                                 {                                     switch (doc.All[i].Name)                                     {                                         case "userCtl":                                             doc.All[i].InnerText = "user01";                                             break;                                         case "passCt1":                                             doc.All[i].InnerText = "mypass";                                             break;                                         case "B1":                                             ClickBtn = doc.All[i]; //提交按鈕                                 break;                                     }                                 }                             }                             ClickBtn.InvokeMember("Click");   //執行按扭操作             }

      2、WebClient封裝了HTTP的一些類，操作簡單，相較於webBrowser，特點是可以自設代理，缺點是對COOKIE的控制      WebClient的運行全在後台，並且提供了非同步作業的能力，這樣很方便並發多個任務，然後等待結果的返回，再逐個處理。多任務非同步呼叫的代碼如下：

private 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")); //開啟WEB;                                 proxy = null;                             }                             catch                             {                             }                         }                     }                     private void Pic_OpenReadCompleted2(object sender, OpenReadCompletedEventArgs e)                     {                             if (e.Error == null)                             {                                         string textData = new StreamReader(e.Result, Encoding.Default).ReadToEnd();  //取返回資訊                              .....                                           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); // 轉化成位元組                                        ((WebClient)sender).UploadDataAsync(new Uri("http://xxxxxxy.com.cn/tp.asp?Id=129"), "POST", byteArray);                             }                      }                     private void Pic_UploadDataCompleted2(object sender, UploadDataCompletedEventArgs e)                     {                              if (e.Error == null)                             {                                 string returnMessage = Encoding.Default.GetString(e.Result);                                 ......                             }                    }

     3、HttpWebRequest較為低層，能實現的功能較多，Cookie操作也很簡單

private bool  PostWebRequest()                            {                                CookieContainer cc = new CookieContainer();                                 string pos tData = "user=" + strUser + "&pass=" + strPsd;                                 byte[] byteArray = Encoding.UTF8.GetBytes(postData); // 轉化                     HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(new Uri("http://www.xxxx.com/chk.asp"));                                 webRequest2.CookieContainer = cc;                                 webRequest2.Method = "POST";                                 webRequest2.ContentType = "application/x-www-form-urlencoded";                                 webRequest2.ContentLength = byteArray.Length;                                 Stream newStream = webRequest2.GetRequestStream();                                 // Send the data.                                 newStream.Write(byteArray, 0, byteArray.Length);    //寫入參數                     newStream.Close();                     HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();                                 StreamReader sr2=new StreamReader(response2.GetResponseStream(), Encoding.Default);                                 string text2 =  sr2.ReadToEnd();                               ......                     }

              HttpWebRequest同樣提供了非同步作業，有興趣的朋友自己查MSDN，實現起來也不難。

 

轉自：http://www.cnblogs.com/yuanbao/archive/2007/08/31/865108.html