string Str = "abc"; // 编码 string BaseStr = Convert.ToBase64String(Encoding.UTF8.GetBytes(Str)); Console.WriteLine(BaseStr);// YWJj // 解码 string OldStr = Encoding.GetEncoding("utf-8").GetString(Convert.FromBase64String(BaseStr)); Console.WriteLine(OldStr); // abc
原文：http://www.cnblogs.com/Cuiy/p/4087708.html