1 正则表达式,regex,webclient下载博客园网页中的一张图片 2  3  4 using System; 5 using System.Collections.Generic; 6 using System.IO; 7 using System.Linq; 8 using System.Net; 9 using System.Text;10 using System.Text.RegularExpressions;11 using System.Threading.Tasks;12 13 namespace ConsoleApplication714 {15     class Program16     {17         static void Main(string[] args)18         {19             WebClient webC = new WebClient();20 21             //博客园的源代码的格式是utf-822             webC.Encoding = Encoding.UTF8;23 24             //读取http://www.cnblogs.com/jinlingzi/p/5936410.html的源代码25             string htmlAdress = @"http://www.cnblogs.com/jinlingzi/p/5936410.html";26             string htmlCode = webC.DownloadString(htmlAdress);27 28             //页面中想要下载的图片的地址是 29             //http://images2015.cnblogs.com/blog/940935/201610/940935-20161007180922395-1514675994.png30 31             //在源代码中图片的地址显示为：32             //<img src="http://www.mamicode.com/http://images2015.cnblogs.com/blog/940935/201610/940935-20161007180922395-1514675994.png"  />33             //<img\ssrc="http://www.mamicode.com/(.+)"\s\s/>34             //图片真实下载地址与源代码中图片的地址相同，由此写正则表达式35             string regularExpression = "<img\\ssrc=http://www.mamicode.com/"((.+))\"\\salt=\"\"\\s/>";36 37             MatchCollection matches= Regex.Matches(htmlCode, regularExpression);38 39             foreach (Match item in matches)40             {41                 //检查用的 Console.WriteLine(item.Groups[1].Value);42 43                 //item.Groups[1].Value下载图片的url     图片下载到本地后，名字是1.png，储存地点是与exe同目录下44                 webC.DownloadFile(item.Groups[1].Value,"1.png");45                 Console.WriteLine("下载成功");46             }47 48             Console.ReadKey();49         }50     }51 }