带枚举的 RegularExpression 属性

Question

My enums have a value of None, which means that a value has not been selected yet. None should never be saved to database.

enum MyEnum
{
    None = 0,
    SomeValue = 1,
...
}

Is there a way I can use Data annotation RegularExpression in such a way that validation should fail if None value is selected?

Answer 1

You'll have a better chance with a [Range(SomeValue, LastValue)] constraint.

Answer 2

I would be tempted to do the following if all your enums define None to be 0:

 [RegularExpression("[1-9][0-9]*", ErrorMessage = "None should never be saved to database.")]
 public MyEnum val { get; set; }