Required attribute for an integer value

Question

I have a viewmodel with an Id property

[Required] public int Id { get; set; } 

But I think this attribute is working only for string properties.

When no Id is set, Id has value 0 and the model is valid.

How can I enforce that if no value for a int property is set, the model will be invalid ?

Answer 1

Use the Range Attribute.

Set minimum to 1 and maximum to int.MaxValue

[Range(1, int.MaxValue, ErrorMessage = "Value for {0} must be between {1} and {2}.")] 

Answer 2

Change the type to Nullable<int> (shortcut int?) to allow null values.