var str = "系统发码：请求参数：【{\"OrderNo\":\"xxxx\",\"UserName\":\"xx\",\"UserTel\":\"xx\"}】,请求结果：【{\"IsSucceed\":false,\"Message\":\"该供应商没有对应的核销员，不允许发码\"}】< br > 系统发码：产品【我在测试】编号【1447】发码失败该供应商没有对应的核销员，不允许发码";            var regStr = "请求结果：【.*\"Message.*\"(?
     
      .*?)\"}】.*系统发码";            Regex reg = new Regex(regStr, RegexOptions.None);            Match mc = reg.Match(str);            var result = mc.Groups["message"].Value;            Console.WriteLine(result);            Console.ReadKey();
     

 

 

 

例子2:

var parIn = "data:image/jpeg;base64,aslkdhfilhweifgaj/skldgfg2ui346";            var regStr = ".*/(?
     
      .*?);.*";            Regex reg = new Regex(regStr, RegexOptions.None);            Match mc = reg.Match(parIn);            var result = mc.Groups["message"].Value;            Console.WriteLine(result);
     

 

显示结果:

jpeg