基于数据注释的验证不适用于导航属性

Question

I have following classes in my program:

class Container
{
    public Container()
    {
        Contain = new Contain();
    }  

    public Contain Contain { get; set; }
}
class Contain
{
    [Required]
    public string Code { get; set; }
}

As you see I decorated the Code property with [Required] data annotation attribute. I wrote a Validate method to validate my objects, too:

class Program
{
    static bool Validate(object command)
    {
        var validationContext = new ValidationContext(command, null, null);
        var validationMessages = new Collection<ValidationResult>();
        var result =  Validator.TryValidateObject(command, validationContext, validationMessages, true);
        Console.WriteLine("********** " + command.GetType().Name +" **************");

        foreach (var validationMessage in validationMessages)
        {
            Console.WriteLine(validationMessage);
        }
        return result;
    }

    static void Main(string[] args)
    {
        var contain = new Contain();
        Console.WriteLine(Validate(contain));

        var container = new Container();
        Console.WriteLine(Validate(container));
        Console.ReadKey();
    }
}

When I run the program the Validate method returns true for container object and returns false for contain :

But the Container contains an invalid contain object(because its Code property set to null ), and so I want the Validate method don't validate it.

Is the any way to do this?

Answer 1

TryValidateObject method doesn't work recursively. Documentation says:

This method evaluates each ValidationAttribute instance that is attached to the object type. It also checks whether each property that is marked with RequiredAttribute is provided. It does not recursively validate the property values of the object.

The workaround is to write your own recursive version of TryValidateObject method. Another solution is a custom validation attribute. For details see this question .