改变状态
import * as Redux from 'redux';
import {Inject, Injectable} from '@angular/core';
@Injectable()
export class exampleService {
    constructor(@Inject(AppStore) private store: Redux.Store<AppState>) {}
    setExampleState(){
       this.store.dispatch(updateExample("new value"));
   }
}
actions.ts
export interface UpdateExapleAction extends Action {
  example?: string;
}
export const updateExample: ActionCreator<UpdateExapleAction> =
   (newVal) => ({
     type: EXAMPLE_CHANGED,
     example: newVal
});