Angular 组件不反映 NGRX 存储状态

Question

我正在玩弄 Angular 和 ngrx，并按照几个不同的教程开始了一些 ngrx-store。我正在使用 ngrx-10 和 angular-11。设置相当简单。

app/store/action.ts

export const toggleSideNav = createAction('[SideNav Component] Toggle', props<{showSideNav?: boolean}>());

app/store/reducer.ts

export interface AppState {
    showSideNav: boolean
}

export const initialState: AppState = {
    showSideNav: true
};

const _appReducer = createReducer(
    initialState,
    on(toggleSideNav, (state: AppState, {showSideNav}) => ({...state, showSideNav: showSideNav ?? !state.showSideNav }))
);

export function AppReducer(state: AppState = initialState, action: Action) {
    return _appReducer(state, action);
}

app.module.ts

...
StoreModule.forRoot({appStore : AppReducer}, {})
...

/访问者（子模块）/components/home.component.ts

@Component({
  selector: 'app-home',
  templateUrl: './home.component.html',
  styleUrls: ['./home.component.scss']
})

export class HomeComponent implements OnInit {

  showSideNav$: Observable<boolean>;

  constructor(private store: Store<AppState>) { 
    this.showSideNav$ = store.pipe(select(x => x.showSideNav))
  }

  ngOnInit(): void {
  }

  toggleSideNav(): void {
    this.store.dispatch(toggleSideNav({}));
  }
}

最后， /访客/components/home.component.html

<div *ngIf="showSideNav$ | async">
    it works
</div>
<button (click)="toggleSideNav()">
    Toggle
</button>

我正在使用 ngrx-devtools，我可以看到“showSideNav”作品的切换。它在 true 和 false 之间摇摆不定，但文本从不显示。好像 showSideNav$ 总是未定义的。

Answer 1

您的选择器 returns undefined。我猜你的选择器函数应该是这样的：

select(x => x.appStore.showSideNav)

Angular 组件不反映 NGRX 存储状态

Angular component does not reflect NGRX store state

angular

ngrx

ngrx-store