Validate decimal value to 2 decimal places with data annotations?

Question

I have this in my view model:

[Required(ErrorMessage = \"Price is required\")]
[Range(0.01, 999999999, ErrorMessage = \"Price must be greater than 0.00\")]
[         


        

Answer 1

I had the same scenario as the OP, yet the answers provided don't give a solution that works for all of the following cases:

12, 12.3 and 12.34

To do that, we use the following regular expression:

[RegularExpression(@"^\d+(.\d{1,2})?$")]

Answer 2

You can also create your own Decimal validation attribute, inheriting from RegularExpressionAttribute:

 public class DecimalAttribute : RegularExpressionAttribute
 {
    public int DecimalPlaces { get; set; }
    public DecimalAttribute(int decimalPlaces)
        : base(string.Format(@"^\d*\.?\d{{0,{0}}}$", decimalPlaces))
    {
        DecimalPlaces = decimalPlaces;
    }

    public override string FormatErrorMessage(string name)
    {
        return string.Format("This number can have maximum {0} decimal places", DecimalPlaces);
    }
 }

and register it to enable client-side validation in Application_Start():

DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(DecimalAttribute), typeof(RegularExpressionAttributeAdapter));