Angular将服务注入基类但不在子类中，并在子类中使用父服务

Question

使用 Angular 7 和 Typescript：我有一个使用大量服务和子类（大约 40 个子类）的基类，我不想在所有子类构造函数中添加这些服务并将它们传递给 @987654322 @ 但我仍然需要在所有子类中使用这些服务。

---

export class parentTool {

    constructor(type: string, public service1: Service1, public service2: Service2,public service3: Service3, public service4: Service4){}
}

export class ChildTool1 extends parentTool {

    constructor(public service1: Service1, public service2: Service2,public service3: Service3, public service4: Service4) {

        super("tool1", service1, service2, service3, service4);
    }
}

export class ChildTool2 extends parentTool {

    constructor(public service1: Service1, public service2: Service2,public service3: Service3, public service4: Service4) {

        super("tool2", service1, service2, service3, service4);
    }
}

Answer 1

我曾经遇到过同样的问题，所以我最终使用 injector 服务进行手动 DI（依赖注入）

这个静态类用于存储注入器服务的引用

export class AppInjector {

  private static injector: Injector;

  static setInjector(injector: Injector) {
    AppInjector.injector = injector;
  }

  static getInjector(): Injector {
    return AppInjector.injector;
  }
}   

在应用模块我设置了injoctor服务

export class AppModule { 
  constructor(injector:Injector){
      AppInjector.setInjector(injector);// save a injector ref ?
  }
}

您需要在开始执行任何 DI（依赖注入）之前存储服务

在基础组件中

export class BaseComponent {
  protected utilitiesService: UtilitiesService; // ? service
  protected loggingService: LoggingService; // ? service

  constructor() {

      const injector = AppInjector.getInjector();

      this.utilitiesService = injector.get(UtilitiesService); // ? DI
      this.loggingService = injector.get(LoggingService); // ? DI


  }

}

子类现在可以访问注入器类注入的所有服务??

    export class ChildComponent extends BaseComponent {
      constructor() {
        super();
      }
    }

demo ??

Answer 2

再添加一项服务并在其中注入所有必需的服务。我们可以简单地将该服务添加到子类中，然后将其传递给父类。

@injectable()
export class ParentService {
    constructor(type: string, private service1: Service1, private service2: Service2,private service3: Service3, private service4: Service4){}
    executeService1(){
        this.service1.method1();
    }
}

export class parentTool {
    constructor(private parentService: ParentService){}
}

export class ChildTool1 extends parentTool {
    constructor(public parentService: ParentService) {
        super("tool1", parentService);
    }
}

export class ChildTool2 extends parentTool {
    constructor(public parentService: ParentService) {
        super("tool2", parentService);
    }
}

Answer 3

您可以使用全局注入器来防止注入所有子类中的所有服务。 在您的情况下，它将是这样的：

import {Injector} from '@angular/core';
//other imports
export class parentTool {
  public service1: Service1
  public service2: Service2
  public service3: Service3
  public service4: Service4
      constructor(type: string,injector: Injector){
        this.serviceInject1 = injector.get(Service1);
        this.serviceInject2 = injector.get(Service2);
        this.serviceInject3 = injector.get(Service3);
        this.serviceInject4 = injector.get(Service4);
      }
  }

  export class ChildTool1 extends parentTool {

      constructor(injector: Injector) {  
          super(injector);
          this.service1.someMethodCall()
      }
  }

  export class ChildTool2 extends parentTool {

      constructor(injector: Injector) {  
          super(injector);
          this.service1.someMethodCall()
      }
  }