知识是通向未来的桥梁
博客是管理知识的手段

参考代码:

using System;
using System.Text.RegularExpressions;
namespace RegexDemo
{
   class Program
   {
       static void Main(string[] args)
       {
           //string phonebook = "(010)88665987 (020)23658945 (021)88965222";
           //string pattern = @"\((\d{3,4})\)(\d{7,8})";
           //string result = Regex.Replace(phonebook, pattern, "$1-$2");
           //Console.WriteLine(result);
           //string phonebook2 = "(010)88665987 (020)23658945 (021)88965222";
           //string pattern2 = @"\((?<areacode>\d{3})\)(?<number>\d{8})";
           //string result2 = Regex.Replace(phonebook2, pattern2, "${areacode}-${number}");
           //Console.WriteLine(result2);
           string imgUrl ="src=\"https://pic.dshow.net/upload/123344.jpg\"";
           string imgUrl2 = "src=\"http://pic.dshow.net/upload/123344.jpg\"";        
           string imgUrl3 = "/upload/agafb/afweff_123344.jpg";
           string imgUrl4 = "src=\"/upload/abd1234_343r_3435/123344.jpg\""; 
           Regex reg = new Regex(@"/upload(/(\w)+)+\.(png|gif|jpg|jpeg|jpg)");
           Regex reg2 = new Regex(@"src=""/upload(/(\w)+)+\.(png|gif|jpg|jpeg|jpg)""");
           Regex reg3 = new Regex(@"src=""/upload");
           Console.WriteLine(reg.IsMatch(imgUrl3));
           Console.WriteLine(reg2.IsMatch(imgUrl4));           
           var rrr = reg2.Matches(imgUrl4);
           foreach(var e in rrr)
           {
               Console.WriteLine("1.匹配到的内容为：" + e.ToString());
           }       
           string input = "这是一段\"包含双引号\"的文本";
           string pattern = @"""([^""]*)""";       
           MatchCollection matches = Regex.Matches(input, pattern);
           foreach (Match match in matches)
           {
               Console.WriteLine("2.匹配到的内容为：" + match.Value);
           }
           string s4 = reg3.Replace(imgUrl4, @"src=""http://localhost/upload");
           Console.WriteLine("3.替换后：" + s4);
       }
   }
}