ChildKernel 上的 Ninject ActivationException

Question

我收到一个 ActivationException，说激活 IEventBroker 时出错。 MyDataSource 接受一个 IEventBroker 有一个参数。如果我不使用子内核，就没有问题。到底是怎么回事？

        var kernel = new StandardKernel();
        var childKernel = new ChildKernel(kernel);
        var eventBroker = new EventBroker();
        childKernel.Bind<IEventBroker>().ToConstant(eventBroker);         
        var myDS = childKernel.Get<MyDataSource>();

Answer 1

来自 ChildKernel readme :

The default behavior of Ninject that classes are bound to themself if not explicit still exists. But in this case this will be done by the top most parent. This means that this class can not have any dependency defined on a child kernel. I strongly suggest to have a binding for all objects that are resolved by ninject and not to use this default behavior.

所以需要显式绑定(bind) MyDataSource自我使其工作:

var kernel = new StandardKernel();
var childKernel = new ChildKernel(kernel);
var eventBroker = new EventBroker();
childKernel.Bind<IEventBroker>().ToConstant(eventBroker);
childKernel.Bind<MyDataSource>().ToSelf();
var myDS = childKernel.Get<MyDataSource>();