Ngrx angular 2我应该如何设置初始状态？

npm install @ngrx/store --save

export interface AppState {
  counter: number;
  user: User;
  // 其他状态属性...
}

import { StoreModule } from '@ngrx/store';
import { appReducer } from './app.reducer';

@NgModule({
  imports: [
    StoreModule.forRoot({ app: appReducer })
  ],
  // 其他模块配置...
})
export class AppModule { }

import { createReducer, on } from '@ngrx/store';
import { increment, decrement } from './counter.actions';
import { AppState } from './app.state';

export const initialState: AppState = {
  counter: 0,
  user: null
  // 其他初始状态属性...
};

export const appReducer = createReducer(
  initialState,
  on(increment, state => ({ ...state, counter: state.counter + 1 })),
  on(decrement, state => ({ ...state, counter: state.counter - 1 }))
  // 其他状态变化处理...
);

import { Component } from '@angular/core';
import { Store, select } from '@ngrx/store';
import { Observable } from 'rxjs';
import { AppState } from './app.state';

@Component({
  selector: 'app-counter',
  template: `
    <div>Counter: {{ counter$ | async }}</div>
    <button (click)="increment()">Increment</button>
    <button (click)="decrement()">Decrement</button>
  `
})
export class CounterComponent {
  counter$: Observable<number>;

  constructor(private store: Store<AppState>) {
    this.counter$ = this.store.pipe(select(state => state.app.counter));
  }

  increment() {
    this.store.dispatch(increment());
  }

  decrement() {
    this.store.dispatch(decrement());
  }
}