react-keep-alive 缓存使用

今天来说说,react 的路由缓存,这个在react 中很少有实质性可用的资料!此篇记录一下

demo 请狠狠的戳这里 ¥  http://download.lllomh.com/cliect/#/product/J804099672377354

demo 请狠狠的戳这里 c   https://download.csdn.net/download/lllomh/12684925

导入 之后 :

import {
    Provider,
    KeepAlive,
} from 'react-keep-alive';

在路由阶段包括起来必须在Router 里层

<Router>
                    <Provider include={['Home','Detaile']}> {/*include ={['Home']} include="a,b"  为组件的弹出名字 匹配就缓存 不写则全部缓存*/}
                        {/*<Switch>*/}
                        {/*    <Route path='/' exact component={Home}/>*/}
                        {/*    <Route path='/home' exact component={Home}/>*/}
                        {/*    <Route path='/detial' exact component={Detaile}/>*/}
                        {/*</Switch>*/}
                    <Switch>
                        <Route path="/home">
                            <KeepAlive name="Home">
                                <Home />
                            </KeepAlive>
                        </Route>
                        <Route path="/detial">
                            <KeepAlive name="Detaile">
                                <Detaile />
                            </KeepAlive>
                        </Route>
                    </Switch>
                    </Provider>
                </Router>

<Provider include={['Home','Detaile']}> 参照 官方文档 https://github.com/lllomh/react-keep-alive

代码:

import React, {Component} from "react"
import { BrowserRouter as Router, Route, Switch, Redirect  } from "react-router-dom"
import axios from 'axios'
import {
    Provider,
    KeepAlive,
} from 'react-keep-alive';

/**路由页面**/
import Home from '../pages/index'
import Detaile from '../pages/detaile'

React.Component.prototype.$axios = axios;



class Routers extends Component {
    render() {
        return (
            <div>

                <Router>
                    <Provider include={['Home','Detaile']}> {/*include ={['Home']} include="a,b"  为组件的弹出名字 匹配就缓存 不写则全部缓存*/}
                        {/*<Switch>*/}
                        {/*    <Route path='/' exact component={Home}/>*/}
                        {/*    <Route path='/home' exact component={Home}/>*/}
                        {/*    <Route path='/detial' exact component={Detaile}/>*/}
                        {/*</Switch>*/}
                    <Switch>
                        <Route path="/home">
                            <KeepAlive name="Home">
                                <Home />
                            </KeepAlive>
                        </Route>
                        <Route path="/detial">
                            <KeepAlive name="Detaile">
                                <Detaile />
                            </KeepAlive>
                        </Route>
                    </Switch>
                    </Provider>
                </Router>

            </div>
        )
    }
}

export default Routers

最后强调一点,要返回操作返回到之前的列表的滚动条位置,需要用 

import {createBrowserHistory} from 'history'


    comeBack=()=>{
        const customHistory = createBrowserHistory();
        customHistory.goBack();
    }

来实现,

"react-keep-alive": "^2.5.2",
"react-router-dom": "^5.2.0",

版本中

 react-keep-alive中有2个使用较多的 生命周期:

进入组件页面的时候 触发:

        componentDidActivate(){
            let home = this.$Tool.getUrlKey("from")
            this.setState({
                isHome:!!home
            })
        }

离开组件页面的时候触发:

       componentWillUnactivate(){
            console.log(444)
        }

总体:

        componentDidMount(){
            console.log('ssssssssssssssssss')
            this.init()
            this.getWatch()

           }

        componentDidActivate(){
        console.log(3333)
            let home = this.$Tool.getUrlKey("from")
            this.setState({
                isHome:!!home
            })
        }
        componentWillUnactivate(){
            console.log(444)
        }

实际线上案例:

FrontendAuth.jsx

        if (targetRouterConfig && !targetRouterConfig.auth && !isLogin) {
            const { component,name } = targetRouterConfig;
            let Components = component
            return <Route exact path={pathname}>
                    <KeepAlive name={name}>
                        <Components/>
                    </KeepAlive>
                  </Route>;
        }

router/index.jsx 

                <Router>
                    <ScrollToTop>
                        <Headers/>
                    <Provider>
                        <Switch>
                            <FrontendAuth routerConfig={routerMap} />
                        </Switch>
                    </Provider>
                        <Footer/>
                    </ScrollToTop>
                </Router>

productDetails.jsx

        componentDidActivate(){
        console.log(3333)
            let home = this.$Tool.getUrlKey("from")
            this.setState({
                isHome:!!home
            })
        }
        componentWillUnactivate(){
            console.log(444)
        }

productDetails.jsx
resetOrNot=()=>{
    this.state.isHome?this.$Tool.comeBack():this.props.history.push('/');

}

最后还是强调重点,这缓存的情况是,只有返回上一步的操作的时候才会定位到原来的滚动条位置,跳转的话,缓存是可以.但滚动位置不会记录.不会再发请求.包括componentWillReceiveProps在内的生命周期都会失效:

只保留 keep-alvie 的生命周期外 shouldComponentUpdate(nextProps,nextState){}、componentDidUpdate(newProps,newState,Snapshot){}

这2个数据生命周期还保留，其他的不执行！

加 Product = bindLifecycle(Product) 的情况下 componentDidUpdate 有效  componentWillReceiveProps不确定,有时有有效,可能有其他原因

     componentDidUpdate(prevProps, prevState, snapshot){
         console.log(111111)
         let categoryId = this.$Tool.getUrlKey("categoryId")
         if(categoryId!=null){
             if(categoryId!=this.state.categoryId){
                 this.init()
             }
         }
     }

这点有点商榷，欢迎大家查证