I know how to create a ValidationAttribute. But how can I check something based on the value of another property?
For example this model :
public class MyModel
{
[Required]
public string FirstName { get; set; }
[Required]
public string LastName { get;set; }
[Required]
public string Country { get; set; }
[CustomValidator(ErrorMessage = "If BE city cannot be null...")]
public string City { get; set; }
}
Country is mandatory but if the Country == "BE" the property City cannot be null.
Is this possible with ValidationAttribute?