Silverlight CustomValidation attribute; ValidationResult.MemberNames.Count == 0

When writing CustomValidation remember to include memberNames in ValidationResult. ValidationResult.MemberNames include property names which are validated at a given moment (are connected to the validation result which we received).

Sample validation should look like the following:

public class CustomValidationMethods
{
    public static ValidationResult SthNumberValidation(string name, ValidationContext validationContext)
    {
        string[] memberNames = new string[] { validationContext.MemberName };

        if (name.StartsWith("B"))
            return ValidationResult.Success;
        else
            return new ValidationResult("Name does not begin with 'B'", memberNames);
    }
}