private void button1_Click(object sender, EventArgs e)        {            string s1 = this.textBox1.Text;            //正则表达式内容            //string match = @"^(http|https|ftp)\://[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(:[a-zA-Z0-9]*)?/?([a-zA-Z0-9\-\._\?\,\'/\\\+&%\$#\=~])*$";            //string match = @"[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(:[a-zA-Z0-9]*)?/?([a-zA-Z0-9\-\._\?\,\'/\\\+&%\$#\=~])*$";            string match = @"[a-zA-z]+://[^\s]*";            //初始化正则表达式实例            Regex reg = new Regex(match);            //开始验证            bool HasValidate = reg.IsMatch(s1);            if (HasValidate)            {                //MessageBox.Show("这是网站有效URL格式。");                try                {                    string tmp = GetHtml(s1);                    string tmpend = StripHTML(tmp);                }                catch (Exception)                {                    //MessageBox.Show("3.该网站只能手动查询！");                }            }        }

 

 

1.获取HTML

GetHtml(String Url)

/// 
        /// 获取有效的HTML        /// 
        ///         /// 
              public String GetHtml(String Url)        {            string sException = null;            string sRslt = null;            string GBsRslt = null;            StreamReader htm = null;            WebResponse oWebRps = null;            WebResponse bWebRps = null;            int a = 0;            WebRequest oWebRqst = WebRequest.Create(Url);            oWebRqst.Timeout = 50000;            WebRequest bWebRqst = WebRequest.Create(Url);            bWebRqst.Timeout = 50000;            try            {                oWebRps = oWebRqst.GetResponse();                bWebRps = bWebRqst.GetResponse();            }            catch (WebException e)            {                sException = e.Message.ToString();                MessageBox.Show(sException);            }            catch (Exception e)            {                sException = e.ToString();                MessageBox.Show(sException);            }            finally            {                if (oWebRps != null)                {                    StreamReader oStreamRd = new StreamReader(                        oWebRps.GetResponseStream(), Encoding.GetEncoding("UTF-8")                        );                    StreamReader GBoStreamRd = new StreamReader(                        bWebRps.GetResponseStream(), Encoding.GetEncoding("GB2312")                        );                    sRslt = oStreamRd.ReadToEnd();                    GBsRslt = GBoStreamRd.ReadToEnd();                    if (!isLuan(sRslt)) //判断utf8是否有乱码                    {                        htm = oStreamRd;                    }                    else                    {                        htm = GBoStreamRd;                    }                    if (htm == oStreamRd)                    {                        a = 1;                    }                    else                    {                        a = 2;                    }                    oStreamRd.Close();                    GBoStreamRd.Close();                    oWebRps.Close();                }            }            if (a == 1)            {                return sRslt;            }            else            {                return GBsRslt;            }        }

  

2.去除HTML标记（正则表达式）

StripHTML(string strHtml)

1         /// 
 2         /// 去除HTML标记 3         /// 
 4         /// 包括HTML的源码  5         /// 
      
       已经去除后的文字
       6         public static string StripHTML(string strHtml) 7         { 8             //regex_str="";//替换为空格 9             string regex_str = "(?is)
      
       ]*>.*?";//替换
       为空格10             strHtml = Regex.Replace(strHtml, regex_str, "");11 12             //regex_str="
       ";//替换
       为空格13             regex_str = "(?is)
       
        ]*>.*?";//替换
        为空格14             strHtml = Regex.Replace(strHtml, regex_str, "");15 16             //regex_str = "( )+";//替换 为空格17             regex_str = "(?i) ";//替换 为空格18             strHtml = Regex.Replace(strHtml, regex_str, " ");19 20             //regex_str = "(\r\n)*";//替换\r\n为空21             regex_str = @"[\r\n]*";//替换\r\n为空22             strHtml = Regex.Replace(strHtml, regex_str, "", RegexOptions.IgnoreCase);23 24             //regex_str = "<[^<]*>";//替换Html标签为空25             regex_str = "<[^<>]*>";//替换Html标签为空26             strHtml = Regex.Replace(strHtml, regex_str, "");27 28             //regex_str = "\n*";//替换\n为空29             regex_str = @"\n*";//替换\n为空30             strHtml = Regex.Replace(strHtml, regex_str, "", RegexOptions.IgnoreCase);31 32             //可以这样33             regex_str = "\t*";//替换\t为空34             strHtml = Regex.Replace(strHtml, regex_str, "", RegexOptions.IgnoreCase);35 36             //可以37             regex_str = "'";//替换'为’38             strHtml = Regex.Replace(strHtml, regex_str, "’", RegexOptions.IgnoreCase);39 40             //可以41             regex_str = " +";//替换若干个空格为一个空格42             strHtml = Regex.Replace(strHtml, regex_str, "  ", RegexOptions.IgnoreCase);43 44             Regex regex = new Regex("<.+?>", RegexOptions.IgnoreCase);45 46             string strOutput = regex.Replace(strHtml, "");//替换掉"<"和">"之间的内容47             strOutput = strOutput.Replace("<", "");48             strOutput = strOutput.Replace(">", "");49             strOutput = strOutput.Replace(" ", "");50 51 52             return strOutput;53 54         }
       
      

 

3.判断是否为乱码（编码）:在StripHTML里调用。

//判断是否为乱码        bool isLuan(string txt)        {            var bytes = Encoding.UTF8.GetBytes(txt);            //239 191 189            for (var i = 0; i < bytes.Length; i++)            {                if (i < bytes.Length - 3)                    if (bytes[i] == 239 && bytes[i + 1] == 191 && bytes[i + 2] == 189)                    {                        return true;                    }            }            return false;        }