Angular X中使用ngrx的方法详解（附源码）

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 --save npm install @ngrx/store --save npm 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