C#三种模拟自动登录和提交POST信息的实现方法

 在实际编程过程中，我们经常会遇到验证身份、程序升级网络投票会员模拟登陆等需要，C#给我们提供了以下的实现方法：
         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：

HtmlDocument doc = webBrowser2.Document;            HtmlElement btn = null;            foreach (HtmlElement em in doc.All)            {                if (em.Name == "username")                {                    em.SetAttribute("value", "name");                }                if (em.Name == "pwd")                {                    em.SetAttribute("value", "password");                }                if (em.Id == "submitBtn")                {                    btn = em;                }            }            btn.InvokeMember("click");

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：

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                {                    //goto:此处有待完善                    //wcArray[idArray].Proxy = new WebProxy(proxy[1], port);                    //wcArray[idArray].OpenReadAsync(new Uri("/tp.asp?Id=129")); //打开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                 //goto:此处有待完善                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("/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);                //goto:此处有待完善            }        }

3、HttpWebRequest较为低层，能实现的功能较多，Cookie操作也很简单

 

SRWebClient类代码：

using System;using System.IO;using System.Net;using System.Web;using System.Windows.Forms;public class SRWebClient{    CookieContainer cookie;    public SRWebClient()    {        cookie = new CookieContainer();    }    /// <TgData>     /// <Alias>下载Web源代码</Alias>     /// </TgData>     public string DownloadHtml(string URL)    {        HttpWebRequest request = HttpWebRequest.Create(URL) as HttpWebRequest;        request.CookieContainer = cookie;        request.AllowAutoRedirect = false;        WebResponse res = request.GetResponse();        string r = "";        StreamReader S1 = new StreamReader(res.GetResponseStream(), System.Text.Encoding.UTF8);        try        {            r = S1.ReadToEnd();        }        catch (Exception ex)        {            MessageBox.Show(ex.Message);        }        finally        {            res.Close();            S1.Close();        }        return r;    }    /// <TgData>     /// <Alias>下载文件</Alias>     /// </TgData>     public long DownloadFile(string FileURL, string FileSavePath)    {        long Filelength = 0;        HttpWebRequest req = HttpWebRequest.Create(FileURL) as HttpWebRequest;        req.CookieContainer = cookie;        req.AllowAutoRedirect = true;        HttpWebResponse res = req.GetResponse() as HttpWebResponse;        System.IO.Stream stream = res.GetResponseStream();        try        {            Filelength = res.ContentLength;            byte[] b = new byte[512];            int nReadSize = 0;            nReadSize = stream.Read(b, 0, 512);            System.IO.FileStream fs = System.IO.File.Create(FileSavePath);            try            {                while (nReadSize > 0)                {                    fs.Write(b, 0, nReadSize);                    nReadSize = stream.Read(b, 0, 512);                }            }            finally            {                fs.Close();            }        }        catch (Exception ex)        {            MessageBox.Show(ex.Message);        }        finally        {            res.Close();            stream.Close();        }        return Filelength;    }    /// <TgData>     /// <Alias>提交数据</Alias>     /// </TgData>     public void Request(string RequestPageURL, RequestData Data)    {        string StrUrl = RequestPageURL;        HttpWebRequest request = HttpWebRequest.Create(StrUrl) as HttpWebRequest;        HttpWebResponse response;        string postdata = Data.GetData();        request.Referer = RequestPageURL;        request.AllowAutoRedirect = false;        request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.01; Windows NT 5.0)";        request.CookieContainer = cookie;        Uri u = new Uri(StrUrl);        if (postdata.Length > 0) //包含要提交的数据　就使用Post方式         {            //作为表单请求             request.ContentType = "application/x-www-form-urlencoded";            //方式就是Post             request.Method = "POST";            //把提交的数据换成字节数组             Byte[] B = System.Text.Encoding.Default.GetBytes(postdata);            request.ContentLength = B.Length;            Stream SW = request.GetRequestStream(); //开始提交数据             SW.Write(B, 0, B.Length);            SW.Close();        }        response = request.GetResponse() as HttpWebResponse;        response.Close();    }}

RequestData类代码：

using System.Collections;using System.IO;public class RequestData{    ArrayList arr = new ArrayList();    public RequestData()    {    }    public string GetData()    {        string r = "";        for (int i = 0; i < arr.Count; i++)        {            data d = (data)arr[i];            if (r.Length > 0)                r += "&";            r += d.Field + "=" + d.Value;        }        return r;    }    public void AddField(string Field, string Value)    {        data a = new data();        a.Field = Field;        a.Value = Value;        arr.Add(a);    }    struct data    {        public string Field, Value;    }}

测试代码：

public void testDownSEOrder()        {            RequestData data = new RequestData();            data.AddField("name", "str");            data.AddField("password", "str");            SRWebClient web = new SRWebClient();            web.Request("url", data);            string s = web.DownloadHtml("url");            textBox1.Text = s;        }