Question

i going to create some validation for custom object in my app. But i have some trouble when try to create CustomValidation rule. My object has field – BirthDay – which not required but if user enter it i need to validate it on simple validation, for example user DataType validation – DataType.DateTime. When i am try to do it i have validation error – BirthDay is required. When i create custom validation and always return true i have same error. Below some lines of code:

[MetadataType(typeof(User.Metadata))]
public class User
{
    #region Metadata        
    private class Metadata
    {
        [Required(ErrorMessage="Name is required")]
        [StringLength(5, ErrorMessage="Max Length is 5")]
        public string Name { get; set; }
        [CustomValidation(typeof(User), "ValidateBirthDay", ErrorMessage="We have trouble.")]
        public DateTime BirthDay { get; set; }

    }
    #endregion

    public static bool ValidateBirthDay(object value)
    {           
        return true;
    }

    public int? ID { get; set; }
    public string Name { get; set; }        
    public DateTime BirthDay { get; set; }
}

p.s. sorry for my English =)

Answer 1

You need to make your propery nullable, ie

public DateTime? BirthDay { get; set; }

so it can have a null value and not required to be set.

Also the way you use the CustomValidation attribute doesn’t seem right. I believe you need to create a class that derives from ValidationAttribute base class and pass its type in CustomValidation attribute’s first param.