[轉貼] C#網頁自動登錄和提交POST信息的多種方法

出處：http://www.cnblogs.com/changyou/archive/2010/01/09/1643169.html

網頁自動登錄和提交POST信息的核心就是分析網頁的源代碼（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、內置JS等問題        WebBrowser是VS2005新提供的組件（其實就是封裝了IE接口），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，並且提供了異步操作的能力，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。多任務異步調用的代碼如下：

    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")); //打開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); // 轉化成二進制數組 
                           ((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(); 
                  ...... 
         }