The .NET Framework also provides us with an alternative, attribute-based validation system in the
System.ComponentModel.DataAnnotations namespace. It is mostly comprised of a wide range of attribute classes that we can decorate our data model properties with, to specify our validation rules. In addition to these attributes, it also includes a few validation classes, which will investigate later.
As an example, let's look at replicating the current validation rules from our
Product class with these data annotation attributes. We need to validate that the
Name property is entered and has a length of twenty-five characters or less, and that the
Price property is more than zero. For the
Name property, we can use the