在Ninject 3.0绑定泛型类型 [英] Binding Generic Types in Ninject 3.0

问题描述

我想Ninject创建绑定的所有类型的实现一个通用接口一个特定的组件内，不指定他们都在运行。有点像开放式泛型如何Autofac工作。

I want Ninject to create Bindings for all types within a specific assembly that implement a generic interface, without specifying them all at runtime. Kind of like how open generics work in Autofac.

这就是我想出了...

This is what i came up with...

kernel.Bind(x => x.FromThisAssembly()
    .SelectAllClasses()
    .Where(t => t.IsAssignableFrom(
        typeof(ICommandHandler<>)))
        .BindAllInterfaces());

调用下面的方法，我希望所有类型实施 ICommandHandler＆LT的数组; T＆GT; ，但它产生什么...

Calling the method below, i would expect an array of all types implementing ICommandHandler<T> but it yields nothing...

public void Process<TCommand>(TCommand command) 
    where TCommand : ICommand
{
    var handlers = 
        _kernel.GetAll<ICommandHandler<TCommand>>();

    foreach(var handler in handlers)
    {
        handler.Handle(command);
    }
}

有没有一个现有的方式来实现这一目标？或者我需要使用的约定API来推出自己的？

Is there an existing way to achieve this? Or do I need to roll my own using the conventions API?

这似乎是一个相当普遍的模式，并想知道这是否可以不写我自己的实现来实现。

It seems like a fairly common pattern and was wondering if this can be achieved without writing my own implementation.

推荐答案

您绑定做是因为两个问题完全无关：

Your binding is doing exactly nothing because of two problems:

1. IsAssignableFrom希望以相反的顺序参数。您指定的

1. IsAssignableFrom expects the parameters in the opposite order. You specified

SomeCommand x = new ICommand<>();

一个封闭泛型类是不能分配给一个开放的泛型类型。或者换句话说

A closed generic class is not assignable to an open generic type. Or in other words

ICommand<> x = new SomeCommand(); 

是无效的code。

is not valid code.

你想要的是：

kernel.Bind(x => x.FromThisAssembly()
                  .SelectAllClasses().InheritedFrom(typeof(ICommandHandler<>))
                  .BindAllInterfaces());

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