字符串替换,该怎么解决

字符串替换
1.string a = "123456789";
2.替换成123***789;
3.用报表表达式里面的方式解决

[解决办法]

C# code

            string a = "123456789";            a = a.Substring(0, 3) + "***" + a.Substring(5, 3);
[解决办法]
C# code
 string a = "12ddd6789"; a = a.Replace(a.Substring(3, 3), "***");