1      /// <summary>
 2         /// WebClient取网页源码
 3         /// </summary>
 4         /// <param name="url"></param>
 5         /// <param name="timout">单位（秒）</param>
 6         /// <param name="proxy"></param>
 7         /// <param name="httpCode">http状态码</param>
 8         /// <returns></returns>
 9         public static string GetHtmlSource(string url, int timout, string proxy, out int httpCode)
10         {
11             try
12             {14                 using (var client = new ExtendedWebClient())
15                 {
16                     client.Timeout = timout * 1000;
17                     client.Proxy = proxy;
18                     client.Encoding = Encoding.UTF8;
19                     string str = client.DownloadString(url);
20 
21                     //验证字符是否有乱码
22                     if (IsLuan(str))
23                     {
24                         Regex reg = new Regex("<meta([^<]*)charset=([^<]*)\"", RegexOptions.IgnoreCase);
25                         Match m = reg.Match(str);
26                         string charset = m.Groups[2].Value;
27                         if (!string.IsNullOrEmpty(charset))
28                         {
29                             string encode = charset.Replace("\"", "");
30                             var data = client.DownloadData(url);
31                             str = new StreamReader(new MemoryStream(data), Encoding.GetEncoding(encode)).ReadToEnd();
32                         }
33                     }
34                     httpCode = 200;
35                     return str;                  
36                 }
37             }
38             catch (Exception ex)
39             {
40                 httpCode = 404;
41                 return ex.Message;
42             }
43         }
44 
45 
46         public class ExtendedWebClient : WebClient
47         {
48             public int Timeout { get; set; }
49             public string Proxy { get; set; }
50 
51             protected override WebRequest GetWebRequest(Uri address)
52             {
53                 HttpWebRequest request = (HttpWebRequest)base.GetWebRequest(address);
54                 //  if (request != null)
55                 request.KeepAlive = false;
56                 request.ProtocolVersion = HttpVersion.Version10;
57                 request.Method = "GET";
58                 request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
59                 request.ServicePoint.Expect100Continue = false;
60                 request.Timeout = Timeout;
61                 request.ReadWriteTimeout = 1000 * Timeout;
62 
63                 ServicePointManager.DefaultConnectionLimit = 50;
64                 if (!string.IsNullOrEmpty(Proxy))
65                     request.Proxy = new WebProxy(Proxy);
66 
67                 return request;
68             }
69 
70             public ExtendedWebClient()
71             {
72 
73 
74             }
75  
76         }

//这是下载图片的方法， 
   private int DownLoadImage(string imgUrl, string url)
        {
            var path = FileHelper.CheckPath(imgUrl, _tmpPath + "\\" + WebTitle);
           try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(imgUrl);
                request.UserAgent = "Mozilla/6.0 (MSIE 6.0; Windows NT 5.1; Natas.Robot)";
                request.Timeout = int.Parse(nudTimeOut.Text) * 1000;

                if (!string.IsNullOrEmpty(txtProxy.Text))
                    request.Proxy = new WebProxy(txtProxy.Text);

                WebResponse response = request.GetResponse();
                Stream stream = response.GetResponseStream();
                if (response.ContentType.ToLower().StartsWith("image/"))
                {
                    using (Image imgPhoto = Image.FromStream(stream))
                    {
  　　　　　　　　　　 //一些判断
 　　　　　　　　　　　　imgPhoto.Save(path);
 　　　　　　　　　　　　return 1;
　　　　　　　　　　　　}  

　　　　　　　　　　｝
catch (WebException)
          　　　　　　  {
             　　　　　　   return 0;
          　　　　　　  }
         　　　　　　   catch (UriFormatException)
          　　　　　　  {
           　　　　　　     return 0;
           　　　　　　 }