C# attribute to check whether one date is earlier than the other

Question

I have a ViewModel for my MVC4 Prject containing two DateTime properties:

[Required]
[DataType(DataType.Date)]
public DateTime RentDate { get; set; }

[Required]         


        

Answer 1

It looks like you're using DataAnnotations so another alternative is to implement IValidatableObject in the view model:

public IEnumerable Validate(ValidationContext validationContext)
{
    if (this.RentDate > this.ReturnDate)
    {
        yield return new ValidationResult("Rent date must be prior to return date", new[] { "RentDate" });
    }
}