c# - Validation a string length : either X or Y, not between X and Y? -

i use validation framework :

[stringlength(10, minimumlength=5)] public string mystring{ get; set; } 

this allows me specify mystring length must between 5 , 10 characters long.

now have check if string either 5 long, or 10 long. no other length allowed. i'm quite sure stringlength attribute inadequate, how ? have extend validation framework , how ?

thx

if can (i'm not familiar validation library in question) can use regular expression.

the regular expression validate character, length 5 or 10, be:

^.{5}(.{5})?$ 

if have digits, can use:

^\d{5}(\d{5})?$