Inject

A constructor parameter decorator that specifies a custom provider of a dependency.

选项说明
token

Injector token that maps to the dependency to be injected.

参见

选项

Injector token that maps to the dependency to be injected.

token: any

使用说明

The following example shows a class constructor that specifies a custom provider of a dependency using the parameter decorator.

class Engine {} @Injectable() class Car { constructor(@Inject('MyEngine') public engine: Engine) {} } const injector = ReflectiveInjector.resolveAndCreate([{provide: 'MyEngine', useClass: Engine}, Car]); expect(injector.get(Car).engine instanceof Engine).toBe(true);

When @Inject() is not present, the Injector uses the type annotation of the parameter as the provider.

class Engine {} @Injectable() class Car { constructor(public engine: Engine) { } // same as constructor(@Inject(Engine) engine:Engine) } const injector = ReflectiveInjector.resolveAndCreate([Engine, Car]); expect(injector.get(Car).engine instanceof Engine).toBe(true);