与 Ninject 2.0 的上下文绑定 [英] Contextual bindings with Ninject 2.0

问题描述

在 Ninject 1.0 中，我有以下绑定定义:

In Ninject 1.0 I had following binding definitions:

Bind<ITarget>().To<Target1>().Only(When.Context.Variable("variable").EqualTo(true));
Bind<ITarget>().To<Target2>();

鉴于这样的绑定我有调用:

Given such bindings I had calls:

ITarget target = kernel.Get<ITarget>(With.Parameters.ContextVariable("variable", true));
ITarget target = kernel.Get<ITarget>(With.Parameters.ContextVariable("variable", false));

第一次调用被解析为 Target1 的实例，第二次调用被解析为 Target2 的实例.

First call was resolved to instance of Target1, second call was resolved to instance of Target2.

如何将其翻译成 Ninject 2.0?

How to translate this into Ninject 2.0?

推荐答案

可以使用元数据，

[Fact]
public void MetadataBindingExample()
{
    string metaDataKey = "key";
    kernel.Bind<IWeapon>().To<Shuriken>().WithMetadata(metaDataKey, true);
    kernel.Bind<IWeapon>().To<Sword>().WithMetadata(metaDataKey, false);
    kernel.Bind<IWeapon>().To<Knife>();

    var weapon = kernel.Get<IWeapon>(metadata => metadata.Has(metaDataKey) && metadata.Get<bool>(metaDataKey));
    Assert.IsType<Shuriken>( weapon );

    weapon = kernel.Get<IWeapon>(metadata => metadata.Has(metaDataKey) && !metadata.Get<bool>(metaDataKey));
    Assert.IsType<Sword>(weapon);

    weapon = kernel.Get<IWeapon>(metadata => !metadata.Has(metaDataKey));
    Assert.IsType<Knife>(weapon);
}

这篇关于与 Ninject 2.0 的上下文绑定的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！