小编Vo *_*oan的帖子

我试图通过 Jasmine 和 Angular 4 测试这两种方法，但this.applicationRef总是返回一个空对象。这个怎么解决？

这是我的代码：

@Injectable()
class Dialog {
  ....
  getRootViewContainerRef(): ViewContainerRef {
    const appInstance = this.applicationRef.components[0].instance;

    if (!appInstance.viewContainerRef) {
      const appName = this.applicationRef.componentTypes[0].name;
      throw new Error(`Missing 'viewContainerRef' declaration in ${appName} constructor`);
    }

    return appInstance.viewContainerRef;
  }
}

createOverlay(parentContainerRef: ViewContainerRef): ComponentRef<DialogContainerComponent> {
  const rootContainerRef = parentContainerRef;
  const rootInjector = rootContainerRef.injector;

  const bindings = ReflectiveInjector.resolve([]);
  const injector = ReflectiveInjector.fromResolvedProviders(bindings, rootInjector);

  const overlayFactory = this.cfr.resolveComponentFactory(DialogContainerComponent);
  return rootContainerRef.createComponent(overlayFactory, rootContainerRef.length, injector);
}

这是我的测试脚本：

describe('Dialog service', () => {
  //let fixture: ComponentFixture<DialogInformationComponent>; …