MVC Validation make RegularExpression numeric only on string field

Question

I have the following property in my view model:

[Required]
[MaxLength(12)]
[MinLength(1)]
[RegularExpression(\"[^0-9]\", ErrorMessage = \"UPRN must be numeri         


        

Answer 1

Or you could do the length validation in the regexp:

[Required]
[RegularExpression("^[0-9]{1,12}$", ErrorMessage = "...")]
public string Uprn { get; set; }

Here's the regex visualized:

Debuggex Demo