c# - Regular expression error message

Question

Using the RegularExpression(@"^d{1,15}$")], I want the user to enter digits up to 15 in length, which returns the error message 'Please enter up to 15 digits for a contact number' if this is not correct

[Required(ErrorMessage = ("Please enter up to 15 digits for a contact number")), Display(Name = "Contact Number"), RegularExpression(@"^d{1,15}$")]
public string ContactNumber { get; set; }

If the user fails to do this I am left with the error message:

The field Contact Number must match the regular expression '^d{1,15}$'.

instead of 'Please enter up to 15 digits for a contact number'...does anyone know why? thanks

Answer 1

You have assigned the ErrorMessage to the RequiredAttribute (which you absolutely don't need in this case because of the regular expression). So:

[Display(Name = "Contact Number")]
[RegularExpression(@"^d{1,15}$", ErrorMessage = "Please enter up to 15 digits for a contact number")]
public string ContactNumber { get; set; }