Question

我想通过连接到 store 来更新我的 Observable，但是当 store 获得值时它没有更新：

在我的组件中，我将任务声明为 Observables：

tasks$: Observable<any> = this.store.pipe(select(state => {
    console.log('state', state);
    return state;
})); // Worked, get the full state

tasks$: Observable<TaskModel[] | undefined> = this.store.select(selectTasks); 
// Doesn't work, can't select tasks from state

减速器：

const tasksReducers = createReducer(
  initialState,
  on(getTasks, (state) => ({...state, isLoading: true})),
  on(getTasksSuccess, (state, result) => ({...state, tasks: result.tasks, isLoading: false}))
);

选择器：

export const selectTasksState = (state: TasksState) => state;

export const selectTasks = createSelector(
  selectTasksState,
  (state: TasksState) => state.tasks
);

效果：

getTasks$ = createEffect(() =>
    this.actions$.pipe(
      ofType(getTasks),
      exhaustMap(action => this.tasksService.getTasks().pipe(
        tap(response => console.log('response', response)),
        map(tasks => getTasksSuccess({tasks})),
        catchError((error: any) => of(getTasksFailure(error)))
      ))
    )
  );

操作：

export const getTasks = createAction(TasksActionTypes.GET_TASKS);
export const getTasksSuccess = createAction(TasksActionTypes.GET_TASKS_SUCCESS, props<{tasks: TaskModel[]}>());
export const getTasksFailure = createAction(TasksActionTypes.GET_TASKS_FAILURE, props<{message: string}>());

状态：

export interface TasksState {
  tasks?: TaskModel[],
  isLoading?: boolean;
  isLoadingSuccess?: boolean;
  isLoadingFailure?: boolean;
}

我认为选择器没有看到状态变化，所以它没有更新，但是在减速器中，我已经创建了一个新对象，所以我不确定我错在哪里

Answer 1

你可以这样做。

在 TS 文件中

selectedData: any;

ngOnInit(): void {
    this.selectedStoreData$ = this.store.select(selectorStoreData);
    
    this.selectedStoreData$.subscribe((data: any) => {
      if (data) {
        this.selectedData= data;
      }
    });
 }

它将订阅数据并将数据存储到 selectedData

当状态更新时，Observable 不会从商店中获取值

1 个答案: