相关疑难解决方法(0)

我想知道是否有一种在Angular2中注入接口的正确方法？(参见下文)

我认为这与接口上缺少的@Injectable()装饰器有关,但似乎不允许这样做.

问候.

当CoursesServiceInterface作为接口实现时,TypeScript编译器会抱怨"CoursesServiceInterface找不到名称":

import {CoursesServiceInterface} from './CoursesService.interface';
import {CoursesService} from './CoursesService.service';
import {CoursesServiceMock} from './CoursesServiceMock.service';
bootstrap(AppComponent, [
  ROUTER_PROVIDERS, 
  GlobalService,
  provide(CoursesServiceInterface, { useClass: CoursesServiceMock })
  ]);

但是使用CoursesServiceInterface作为接口:

import {Injectable} from 'angular2/core';
import {Course} from './Course.class';
//@Injectable()
export interface CoursesServiceInterface {
    getAllCourses(): Promise<Course[]>;//{ return null; };
    getCourse(id: number): Promise<Course>;// { return null; };
    remove(id: number): Promise<{}>;// { return null; };
}

当service是一个类时,TypeScript编译器不再抱怨:

import {Injectable} from 'angular2/core';
import {Course} from './Course.class';
@Injectable()
export class CoursesServiceInterface {  
    getAllCourses() : Promise<Course[]> { return null; …

我无法在 Ionic 5 中实现 canDeactivate 防护。以下是我的代码。

模型.ts

export interface isDeactivatable {
    canDeactivate: () => Observable<boolean> | Promise<boolean> | boolean;
 }

离开页面.guard.ts

export class LeavePageGuard implements CanDeactivate<isDeactivatable>{
  canDeactivate(
    component: isDeactivatable
  ): Observable<boolean> | Promise<boolean> | boolean {
    console.log('LeavePageGuard');
    return component.canDeactivate();
  }

}

测试页.ts

export class TestPage implements OnInit, isDeactivatable{
      canDeactivate(): Observable<boolean> | Promise<boolean> | boolean {
        console.log('canDeactivate in TestPage');
        return true;
      }
}

本地路由.Module.ts

const routes: Routes = [
  {
    path: '',
    component: HomePage,
    children:[
      {
        path: 'test',
        loadChildren: () => …