正则表达式样例征求！

Question

msdn上有现成的例子，而且讲得很详细，具体什么方位我记不清了

Answer 1

验证输入字符是否全部为英文字符
System.String ex = @"^\w+$";              System.Text.RegularExpressions.Regex reg = new Regex( ex );                              bool flag = reg.IsMatch( str );验证邮件格式
System.String ex = @"^\w+@\w+\.\w+$";System.Text.RegularExpressions.Regex reg = new Regex( ex );bool flag = reg.IsMatch( str );
从 URL 提取协议和端口号
String Extension(String url)    {      Regex r = new Regex(@"^(?<proto>\w+)://[^/]+?(?<port>:\d+)?/",         RegexOptions.Compiled);      return r.Match(url).Result("${proto}${port}");    }
要得到不以数字开头的字符组合
(?<!\d)[a-zA-Z]{2,}

Answer 2

http://samples.gotdotnet.com/quickstart/util/srcview.aspx?path=%2fquickstart%2fhowto%2fsamples%2fRegularExpressions%2fRegexMatch%2fRegexMatch.src

Answer 3

http://samples.gotdotnet.com/quickstart/util/srcview.aspx?path=%2fquickstart%2fhowto%2fsamples%2fRegularExpressions%2fRegexMatch%2fRegexMatch.src

Answer 4

 as follows: http://expert.csdn.net/Expert/topic/1930/1930163.xml?temp=.5256006