Is there out-of-the box validator for Enum values in DataAnnotations namespace?

Question

C# enum values are not limited to only values listed in it\'s definition and may store any value of it\'s base type. If base type is not defined than Int32 or s

Answer 1

There's EnumDataType in .NET4+ ...

Make sure you set the 3rd parameter, validateAllProperties=true in the call to ValidateObject

so from your example:

public class Entity
{
    [EnumDataType(typeof(MyEnum))]
    public MyEnum EnumValue { get; set; }
}

[Fact]
public void TestInvalidEnumValue()
{
    Entity entity = new Entity { EnumValue = (MyEnum)(-126) };
    // -126 is stored in the entity.EnumValue property

    Assert.Throws(() =>
        Validator.ValidateObject(entity, new ValidationContext(entity, null, null), true));
}