【EasyNetQ】- 多态发布和订阅

您可以订阅接口，然后发布该接口的实现。

我们来看一个例子。我有一个接口IAnimal和两个实现Cat和Dog：

public interface IAnimal

{

    string Name { get; set; }

}

public class Cat : IAnimal

{

    public string Name { get; set; }

    public string Meow { get; set; }

}

public class Dog : IAnimal

{

    public string Name { get; set; }

    public string Bark { get; set; }

}

我可以订阅IAnimal并接收Cat和Dog类：

bus.Subscribe<IAnimal>("polymorphic_test", @interface =>

    {

        var cat = @interface as Cat;

        var dog = @interface as Dog;

        if (cat != null)

        {

            Console.Out.WriteLine("Name = {0}", cat.Name);

            Console.Out.WriteLine("Meow = {0}", cat.Meow);

        }

        else if (dog != null)

        {

            Console.Out.WriteLine("Name = {0}", dog.Name);

            Console.Out.WriteLine("Bark = {0}", dog.Bark);

        }

        else

        {

            Console.Out.WriteLine("message was not a dog or a cat");

        }

    });

让我们发布一只猫和一只狗：

var cat = new Cat

{

    Name = "Gobbolino",

    Meow = "Purr"

};

var dog = new Dog

{

    Name = "Rover",

    Bark = "Woof"

};

bus.Publish<IAnimal>(cat);

bus.Publish<IAnimal>(dog);

请注意，我必须明确指定我发布IAnimal。EasyNetQ使用发布和订阅方法中指定的泛型类型将发布路由到订阅。