asp.net mvc 3 - MVC3 How To Phone Validation for model structure? -

in model structure phonenumber not required if user want enter value, must entered 10 digits. tried

[stringlength(10, minimumlength = 10, errormessage = "girdiğiniz numara 10 karakter uzunluğunda olmalı")]

but doesn't allow empty entry. there have idea?

use regular expression validator , find/write regular expression validates phone number. example in usa:

public class myregularexpressions {    public const string usphone = @"^[2-9]\\d{2}-\\d{3}-\\d{4}$|^[2-9]\\d{2}\\d{3}\\d{4}$"; }

and atribute used in model is:

[regularexpression(myregularexpressions.usphone)] public string phonenumber { get; set; }

this way not required when entered has match specified regular expression.

if need write own regular expression 1 of best sites out there is: http://www.regexr.com/

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