Question

尝试在NgRx中使用参数化查询，但结果为空。

这是下面的代码的堆叠版本：https://stackblitz.com/edit/ngrx-parameterized-query

还原代码

export const userAdapter = createEntityAdapter<UserModel>({
  selectId: x => x.UserId
});
export interface UserlistState extends EntityState<UserModel>{

};

export const initialState: UserlistState = userAdapter.getInitialState({

}); 


export function UserlistReducers(
  state: UserlistState = initialState,
  action: actions.UserlistActions
){
  switch(action.type){

    case actions.UserlistActionTypes.UPSERT_USERS:
      return userAdapter.upsertMany(action.users,state);

    default:
      return state;
  }
}

export const getUserlistState = createFeatureSelector<UserlistState>('userlist');

export const {
  selectIds,
  selectEntities,
  selectAll,
  selectTotal
} = userAdapter.getSelectors(getUserlistState);

export const getUsersByOrganizationId = createSelector(selectAll,
    (users: Array<UserModel>, organization_id: number)=>{
        return users.filter(x=> x.OrganizationId == organization_id)
    }
)

用法

watchlist = ():Observable<UserModel[]> =>{
        return this.userlistStore.select(reducers.selectAll);
    }

    watchlistByOrganizationId = (organization_id: number): Observable<UserModel[]> =>{
        return this.userlistStore.select(reducers.getUsersByOrganizationId(organization_id));
    }

Answer 1

您的选择器错误。

这应该是这样； organization_id是选择器函数的参数，因此它在函数范围内可用，因此无需在箭头函数参数列表中添加它。 selectAll将返回用户并将其作为参数传递给arrow函数。以下应该可以正常工作！

export const getUsersByOrganizationId = (organization_id: number) => createSelector(selectAll,
  (users: Array<UserModel>) => {
    return users.filter(x => x.OrganizationId == organization_id)
  }
);

StackBlitz without errors.

NgRx参数化选择器显示空结果

1 个答案: