前言

ngrx 是 Angular框架的状态容器，提供可预测化的状态管理。下面话不多说，来一起看看详细的介绍：

1.首先创建一个可路由访问的模块 这里命名为：DemopetModule。

包括文件：demopet.html、demopet.scss、demopet.component.ts、demopet.routes.ts、demopet.module.ts

代码如下：

demopet.html

<!--暂时放一个标签--><h1>Demo</h1>

demopet.scss

h1{ color:#d70029;}

demopet.component.ts

import { Component} from '@angular/core';@Component({ selector: 'demo-pet', styleUrls: ['./demopet.scss'], templateUrl: './demopet.html'})export class DemoPetComponent { //nothing now...}

demopet.routes.ts

import { DemoPetComponent } from './demopet.component';export const routes = [ { path: '', pathMatch: 'full', children: [ { path: '', component: DemoPetComponent } ] }];

demopet.module.ts

import { CommonModule } from '@angular/common';import { FormsModule } from '@angular/forms';import { NgModule } from '@angular/core';import { RouterModule } from '@angular/router';import { routes } from './demopet.routes';@NgModule({ declarations: [ DemoPetComponent, ], imports: [ CommonModule, FormsModule, RouterModule.forChild(routes) ], providers: [ ]})export class DemoPetModule {}

整体代码结构如下：

运行效果如下：只是为了学习方便，能够有个运行的模块

2.安装ngrx

npm install @ngrx/core --savenpm install @ngrx/store --savenpm install @ngrx/effects --save

@ngrx/store是一个旨在提高写性能的控制状态的容器

3.使用ngrx

首先了解下单向数据流形式

代码如下：

pet-tag.actions.ts

import { Injectable } from '@angular/core';import { Action } from '@ngrx/store';@Injectable()export class PettagActions{ static LOAD_DATA='Load Data'; loadData():Action{ return { type:PettagActions.LOAD_DATA }; } static LOAD_DATA_SUCCESS='Load Data Success'; loadDtaSuccess(data):Action{ return { type:PettagActions.LOAD_DATA_SUCCESS, payload:data }; } static LOAD_INFO='Load Info'; loadInfo():Action{ return { type:PettagActions.LOAD_INFO }; } static LOAD_INFO_SUCCESS='Load Info Success'; loadInfoSuccess(data):Action{ return { type:PettagActions.LOAD_INFO_SUCCESS, payload:data }; }}

pet-tag.reducer.ts

import { Action } from '@ngrx/store';import { Observable } from 'rxjs/Observable';import { PettagActions } from '../action/pet-tag.actions';export function petTagReducer(state:any,action:Action){ switch(action.type){ case PettagActions.LOAD_DATA_SUCCESS:{ return action.payload; } // case PettagActions.LOAD_INFO_SUCCESS:{ // return action.payload; // } default:{ return state; } }}export function infoReducer(state:any,action:Action){ switch(action.type){ case PettagActions.LOAD_INFO_SUCCESS:{ return action.payload; } default:{ return state; } }}

NOTE:Action中定义了我们期望状态如何发生改变 Reducer实现了状态具体如何改变

Action与Store之间添加ngrx/Effect 实现action异步请求与store处理结果间的解耦

pet-tag.effect.ts

import { Injectable } from '@angular/core';import { Effect,Actions } from '@ngrx/effects';import { PettagActions } from '../action/pet-tag.actions';import { PettagService } from '../service/pet-tag.service';@Injectable()export class PettagEffect { constructor( private action$:Actions, private pettagAction:PettagActions, private service:PettagService ){} @Effect() loadData=this.action$ .ofType(PettagActions.LOAD_DATA) .switchMap(()=>this.service.getData()) .map(data=>this.pettagAction.loadDtaSuccess(data)) @Effect() loadInfo=this.action$ .ofType(PettagActions.LOAD_INFO) .switchMap(()=>this.service.getInfo()) .map(data=>this.pettagAction.loadInfoSuccess(data));}

4.修改demopet.module.ts 添加 ngrx支持

import { StoreModule } from '@ngrx/store';import { EffectsModule } from '@ngrx/effects';import { PettagActions } from './action/pet-tag.actions';import { petTagReducer,infoReducer } from './reducer/pet-tag.reducer';import { PettagEffect } from './effect/pet-tag.effect';@NgModule({ declarations: [ DemoPetComponent, ], imports: [ CommonModule, FormsModule, RouterModule.forChild(routes), //here new added StoreModule.provideStore({ pet:petTagReducer, info:infoReducer }), EffectsModule.run(PettagEffect) ], providers: [ PettagActions, PettagService ]})export class DemoPetModule { }

5.调用ngrx实现数据列表获取与单个详细信息获取

demopet.component.ts

import { Component, OnInit, ViewChild, AfterViewInit } from '@angular/core';import { Observable } from "rxjs";import { Store } from '@ngrx/store';import { Subscription } from 'rxjs/Subscription';import { HttpService } from '../shared/services/http/http.service';import { PetTag } from './model/pet-tag.model';import { PettagActions } from './action/pet-tag.actions';@Component({ selector: 'demo-pet', styleUrls: ['./demopet.scss'], templateUrl: './demopet.html'})export class DemoPetComponent { private sub: Subscription; public dataArr: any; public dataItem: any; public language: string = 'en'; public param = {value: 'world'}; constructor( private store: Store<PetTag>, private action: PettagActions ) { this.dataArr = store.select('pet'); } ngOnInit() { this.store.dispatch(this.action.loadData()); } ngOnDestroy() { this.sub.unsubscribe(); } info() { console.log('info'); this.dataItem = this.store.select('info'); this.store.dispatch(this.action.loadInfo()); }}

demopet.html

<h1>Demo</h1><pre> <ul> <li *ngFor="let d of dataArr | async"> DEMO : {{ d.msg }} <button (click)="info()">info</button> </li> </ul> {{ dataItem | async | json }} <h1 *ngFor="let d of dataItem | async"> {{ d.msg }} </h1></pre>

6.运行效果

初始化时候获取数据列表

点击info按钮 获取详细详细

7.以上代码是从项目中取出的部分代码，其中涉及到HttpService需要自己封装，data.json demo.json两个测试用的json文件，名字随便取的当时。

http.service.ts

import { Inject, Injectable } from '@angular/core';import { Http, Response, Headers, RequestOptions, URLSearchParams } from '@angular/http';import { Observable } from "rxjs";import 'rxjs/add/operator/map';import 'rxjs/operator/delay';import 'rxjs/operator/mergeMap';import 'rxjs/operator/switchMap';import 'rxjs/add/operator/catch';import 'rxjs/add/observable/throw';import { handleError } from './handleError';import { rootPath } from './http.config';@Injectable()export class HttpService { private _root: string=""; constructor(private http: Http) { this._root=rootPath; } public get(url: string, data: Map<string, any>, root: string = this._root): Observable<any> { if (root == null) root = this._root; let params = new URLSearchParams(); if (!!data) { data.forEach(function (v, k) { params.set(k, v); }); } return this.http.get(root + url, { search: params }) .map((resp: Response) => resp.json()) .catch(handleError); }}

8.模块源代码

下载地址

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对的支持。