记录一下C#中使用正则表达式

        private static void Main(string[] arg)
        {
            var text = "";
            //文本读取器
            using (TextReader reader = new StreamReader(@"D:\Users\admin\Desktop\cstext.txt", System.Text.Encoding.UTF8))
            {
                //一次性读完
                string textContent = reader.ReadToEnd();
                //输出读取的内容
                //Console.WriteLine(textContent);
                text = textContent;
            }

            string par = "";
            Regex reg = new Regex(@"(?<gr1><div\spage-id=.[0-9]{4})(?<gr2>.\sdata-cms=.[a-z]{7}.)");
            var a = reg.Matches(text);
            var b = a[0].Groups["gr1"].Value;
            //Console.WriteLine(a.Value);
        }

1.匹配任意字符  .

2.匹配4个0-9的数字[0-9]{4}

3.匹配4个a-z字母 [a-z]{4}

4.（?<gr1>）给正则表达式分组方便使用group["组名"]来提取中间的数据

详见msdn官方文档  https://learn.microsoft.com/zh-cn/dotnet/standard/base-types/character-classes-in-regular-expressions