'加密代码
Dim Str as string=System.Convert.ToBase64String(System.Text.Encoding.Default.GetBytes("aaaaaaaaaaaaaaaaaaaaaaaaaa"))
'解密代码
Dim Str as string = System.Text.Encoding.Default.GetString(System.Convert.FromBase64String("YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWE="))
