Vue实例及生命周期

1,Vue实例生命周期.

  • 有时候,我们需要在实例创建过程中进行一些初始化的工作,以帮助我们完成项目中更复杂更丰富的需求,开发,针对这样的需求,Vue提供给我们一系列的钩子函数

Vue.js实例生命周期

2,Vue生命周期的阶段

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">
    {{ name }}
    <button @click="myClick">点击修改数据</button>
</div>
<script>
    new Vue({
        el: "#app",
        data: {
            name: "雪人"
        },
        methods: {
            init: function () {
                console.log(this.name)
            },
            myClick: function () {
                this.name = "雪雪";
            }
        },
        beforeCreate() {
            console.group("beforeCreate");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.name);
            console.log("init", this.init);
            console.log("innerHTML", document.getElementById("app"))
        },

</script>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">
    {{ name }}
    <button @click="myClick">点击修改数据</button>
</div>
<script>
    new Vue({
        el: "#app",
        data: {
            name: "雪人"
        },
        methods: {
            init: function () {
                console.log(this.name)
            },
            myClick: function () {
                this.name = "雪雪";
            }
        },
  created() {
            console.group("Created");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.name);
            console.log("init", this.init);
            console.log("innerHTML", document.getElementById("app"))
        },
</script>
</body>
</html>

 
 
<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.min.js"></script>
</head>
<body>

<div id="app">
{{ name }}
<button @click="myClick">点击修改数据</button>
</div>
<script>
new Vue({
el: "#app",
data: {
name: "雪人"
},
methods: {
init: function () {
console.log(this.name)
},
myClick: function () {
this.name = "雪雪";
}
},

beforeMount() {
console.group("beforeMount");
console.log("el", this.$el);
console.log("data", this.$data);
console.log("name", this.name);
console.log("init", this.init);
console.log("innerHTML", document.getElementById("app"))
},
</script>
</body>
</html>
 

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">
    {{ name }}
    <button @click="myClick">点击修改数据</button>
</div>
<script>
    new Vue({
        el: "#app",
        data: {
            name: "雪人"
        },
        methods: {
            init: function () {
                console.log(this.name)
            },
            myClick: function () {
                this.name = "雪雪";
            }
        },

        mounted() {
            console.group("mounted");
            console.log("el: ", this.$el);
            console.log("data: ", this.$data);
            console.log("name: ", this.name);
            console.log('myClick', this.myClick);
            console.log("innerHTML: ", document.getElementById("app"));
        },

</script>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">
    {{ name }}
    <button @click="myClick">点击修改数据</button>
</div>
<script>
    new Vue({
        el: "#app",
        data: {
            name: "雪人"
        },
        methods: {
            init: function () {
                console.log(this.name)
            },
            myClick: function () {
                this.name = "雪雪";
            }
        },
       
        beforeUpdate(){
            console.group("beforeUpdate");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.name);
            console.log("myClick", this.myClick);
            console.log("innerHTML:", document.getElementById("app"));
        },
</script>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">
    {{ name }}
    <button @click="myClick">点击修改数据</button>
</div>
<script>
    new Vue({
        el: "#app",
        data: {
            name: "雪人"
        },
        methods: {
            init: function () {
                console.log(this.name)
            },
            myClick: function () {
                this.name = "雪雪";
            }
        },
       
        updated(){
            console.group("updated");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.name);
            console.log("myClick", this.myClick);
            console.log("innerHTML:", document.getElementById("app"))
        },

</script>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">
    <App></App>
</div>
<script>
    // Vue生命周期的消亡
    let Laside = {
        template: `
            <div>
                <h1>{{ mes }}</h1>
            </div>
        `,
        data() {
            return {
                mes: "Hello 雪人"
            }
        },
        methods: {
            changeData: function() {
                this.mes = "帅爆太阳的男人 is here!";
            }
        },
        // 组件的创建和销毁对性能有影响
        beforeDestroy(){
            console.log("beforeDestroy");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.mes);
            console.log("innerTEXT:", document.getElementById("app").innerText);
            console.log("innerHTML:", document.getElementById("app").innerHTML);
        }
    };
    let App = {
        template: `
            <div>
                <laside v-if="isShow"></laside>
                <button @click="showHide">创建消除组件</button>
            </div>
        `,
        // 判断有嵌套的子组件
        components: {
            "Laside": Laside,
        },
        methods: {
            showHide:function(){
                this.isShow = !this.isShow;
            }
        },
        data(){
            return {
                isShow: true,
            }
        }
    };
    new Vue({
        el: "#app",
        components:{
            App,
        }
    })
</script>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">

</div>
<script>

    // Vue生命周期的消亡
    let Laside = {
        template: `
            <div>
                <h1>{{ mes }}</h1>
            </div>
        `,
        data() {
            return {
                mes: "Hello 雪人"
            }
        },
        methods: {
            changeData: function() {
                this.mes = "帅爆太阳的男人 is here!";
            }
        },
        
        destroyed(){
            console.log("destroyed");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name: ", this.mes);
        }
    };
    let App = {
        template: `
            <div>
                <laside v-if="isShow"></laside>
                <button @click="showHide">创建消除组件</button>
            </div>
        `,
        // 判断有嵌套的子组件
        components: {
            "Laside": Laside,
        },
        methods: {
            showHide:function(){
                this.isShow = !this.isShow;
            }
        },
        data(){
            return {
                isShow: true,
            }
        }
    };
    new Vue({
        el: "#app",
        template: `<App></App>`,
        components:{
            App,
        }
    })
</script>
</body>
</html>

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.min.js"></script>
</head>
<body>

<div id="app">

</div>
<script>
    

    // Vue生命周期的消亡
    let Laside = {
        template: `
            <div>
                <h1>{{ mes }}</h1>
            </div>
        `,
        data() {
            return {
                mes: "Hello 雪人"
            }
        },
        methods: {
            changeData: function() {
                this.mes = "帅爆太阳的男人 is here!";
            }
        },

        activated(){
            console.log("activated");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.mes);
        },
        deactivated(){
            console.group("deactivated");
            console.log("el", this.$el);
            console.log("data", this.$data);
            console.log("name", this.mes);
        },
    };
    let App = {
        template: `
            <div>
                <laside v-if="isShow"></laside>
                <button @click="showHide">创建消除组件</button>
            </div>
        `,
        // 判断有嵌套的子组件
        components: {
            "Laside": Laside,
        },
        methods: {
            showHide:function(){
                this.isShow = !this.isShow;
            }
        },
        data(){
            return {
                isShow: true,
            }
        }
    };
    new Vue({
        el: "#app",
        template: `<App></App>`,
        components:{
            App,
        }
    })
</script>
</body>
</html>

***activated和deactivated在浏览器上无明显效果,只是在虚拟的DOM树发生了变化***

 2.1,VueRouter的实现原理

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>路由</title>
</head>
<body>
<div id="app">

</div>
<script>
    // 先获取到div这个标签
    let oDiv = document.getElementById("app");

    // window窗口的onhashchange函数,内部其实就是这个原理,不加break会继续向下执行
    window.onhashchange = function () {
        switch (location.hash) {
            case '#/login':
                oDiv.innerHTML = `<h1>这是登录页面</h1>`;
                break;
            case '#/register':
                oDiv.innerHTML = `<h1>这是注册页面</h1>`;
                break;
            default:
                oDiv.innerHTML = `<h1>这是首页</h1>`;
                break
        }
    }
</script>
</body>
</html>

2.2Vue路由安装的五大步骤

重中之重:先把router导进来

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>安装使用</title>
    <script src="vue.min.js"></script>
    <script src="vue-router.js"></script>
</head>
<body>

<div id="app">

</div>
<script>
    // 1,在Vue根实例中使用,VueRouter,固定写法,据说以后会用,但不知道有什么用
    Vue.use(VueRouter);

    let Home = {
        template: `
            <div>
                <h1>这是主页页面</h1>
            </div>
        `
    };

    let Login = {
        template: `
            <div>
                <h1>这是登录页面</h1>
            </div>
        `
    };

    let Register = {
        template: `
            <div>
                <h1>这是注册页面</h1>
            </div>
        `
    };

    let App = {
        // 第四步, router-link会渲染成a标签, to会变成href属性, to后面是router中定义的路径
        // 第五步, router-view是页面的渲染出口
        template: `
            <div>
                <router-link to="/">首页</router-link>
                <router-link to="/login">登录</router-link>
                <router-link to="/register">注册</router-link>
                <router-view></router-view>
            </div>
        `
    };

    // 第二步实例化一个router对象, 本质上是将路径和页面内容绑定了对应关系
    let router = new VueRouter({
        routes: [
            {
                path: '/',
                component: Home,
            },
            {
                path: '/login',
                component: Login,
            },
            {
                path: '/register',
                component: Register,
            }
        ]
    });

    new Vue({
        el: "#app",
        template:`<App></App>`,
        // 第三步,在根实例中注册router对象
        router:router,
        components:{
            App,
        }
    })
</script>
</body>
</html>

2.3路由重命名

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>命名</title>
    <script src="vue.min.js"></script>
    <script src="vue-router.js"></script>
</head>
<body>

<div id="app">

</div>
<script>
    // 1,在vue根实例中使用,VueRouter
    Vue.use(VueRouter);

    // 这是主页面的组件
    let Home = {
        template: `
            <div>
                <h1>这是主页面</h1>
            </div>
        `
    };

    // 这是登录页面的组件
    let Login = {
        template: `
            <div>
                <h1>这是登录页面</h1>
            </div>
        `
    };

    // 这是注册页面的组件
    let Register = {
        template: `
            <div>
                <h1>这是注册页面</h1>
            </div>
        `
    };

    // 写一个组件的统一入口,
    // 第四步,router-link会渲染成a标签,to会变成href属性, to后面是router中定义路径
    // 第五步,router-view是页面内容的渲染出口
    // 重命名类似于反向解析
    let App = {
        template: `
            <div>
               <router-link :to="{ name:'home' }">首页</router-link>
               <router-link :to="{ name:'login' }">登录</router-link>
               <router-link :to="{ name:'register' }">注册</router-link>
               <router-view></router-view>
            </div>
        `
    };

    // 实例化一个router对象:本质是将路径和页面内容绑定了对应关系
    let router = new VueRouter({
        routes: [
            {
                name: 'home',
                path: '/',
                component: Home,
            },
            {
                name: 'login',
                path:'/login',
                component:Login,
            },
            {
                name: 'register',
                path:'/register',
                component: Register,
            }
        ]
    });

    // 第三步把router注册在根实例中
    new Vue({
        el:"#app",
        template: `<App></App>`,
        router: router,
        components:{
            App,
        }
    })
</script>
</body>
</html>

2.4,VueRouter值路由参数之参数

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>路由参数</title>
    <script src="vue.min.js"></script>
    <script src="vue-router.js"></script>
</head>
<body>

<div id="app">

</div>
<script>
    //  在真实的场景中,可以有以下路形式
    // user/1,
    // user/userID:1
    // 1,在Vue根实例中使用.VueRouter
    Vue.use(VueRouter);

    // 这是主页面的组件
    let Home = {
        template: `
            <div>
                <h1>这是主页面</h1>
            </div>
        `
    };

    // 伪造一个用户信息的组件
    let userParams = {
        template: `
            <div>
                <h1>这是用户一的信息</h1>
            </div>
        `
    };

    //手写一个所有组件的入口,参数的重中之重,这个参数是在to的后边在写一个字典,params:{userId:1}
    let App = {
        // router-link会渲染成a标签,to会变成href属性,to后面中定义的路径
        // router-view是页面内容的渲染出口
        template:`
            <div>
            <router-link :to="{ name:'home' }">首页</router-link>
            <router-link :to="{ name:'userParams', params:{userId:1} }">登录</router-link>
            <router-link :to="{ name:'userQuery', query: { userId:2 } }">注册</router-link>
            <router-view></router-view>
</div>
        `
    };
    // 伪造一个用户二的信息的组件
    let userQuery = {
        template: `
            <div>
                <h1>这是用户二的信息</h1>
            </div>
        `
    };

    // 实例化一个router的对象
    // 本质上是将路径和页面内容绑定了对应关系
    let router = new VueRouter({
        routes:[
            {
                name:'home',
                path:'/',
                // 把Home注册到router中
                component:Home,
            },
            {
                name:'userParams',
                path:'/user/:userId',
                // 把userParams注册到router中
                component:userParams,
            },
            {
                name:'userQuery',
                path:'/user',
                // 把userQuery注册到router中
                component:userQuery,
            }
        ]
    });

    // 在根实例中注册router对象
    new Vue({
        el: "#app",
        template: `<App></App>`,
        router: router,
        components:{
            App,
        }
    })
</script>
</body>
</html>

 2.5,VueRouter路由之子路由

用重名就可以进行子路由的切换

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>写死路径的很不怎么样的子路由</title>
    <script src="vue.min.js"></script>
    <script src="vue-router.js"></script>
</head>
<body>

<div id="app">

</div>
<script>
    //手写一个不怎么样的主页面的组件
    let Home = {
        template:`
            <div>
                <h1>这是主页面</h1>
            </div>
        `
    };

    //手写一个不怎么样的课程页面
    let Courses = {
        template:`
            <div>
                <h1>这是课程页面</h1>
                <router-link :to="{ name:'lightcourses' }">轻课</router-link>
                <router-link :to="{ name:'degreecourses' }">学位课</router-link>
                <router-view></router-view>
            </div>
        `
    };
    // 这回要不把这两个先注册到App中吧
    let App = {
        template:`
            <div>
                <router-link :to="{ name:'home' }">首页</router-link>
                <router-link :to="{ name:'courses' }">课程页面</router-link>
                <router-view></router-view>
            </div>
        `
    };
    //写一个课程里边的轻课的子路由
    let LightCourses = {
         template:`
            <div>
                <h1>这是轻课的页面</h1>
            </div>
         `
    };
    //写一个学位课的页面
    let DegreeCourses = {
        template:`
            <div>
                <h1>这是学位课的页面</h1>
            </div>
        `
    };
    //把这俩货写到courses中

    //实例化一个VueRouter的对象
    let router = new VueRouter({
        routes:[
            {
                name: 'home',
                path: '/',
                component:Home
            },
            {
                name:'courses',
                path: '/courses',
                component:Courses,
                //把课程的子路由注册进来,要不然不能点
                children:[
                    {
                        name:'lightcourses',
                        path: '/lightcourses',
                        component:LightCourses,
                    },
                    {
                        name:'degreecourses',
                        path:'/degreecourses',
                        component:DegreeCourses
                    }
                ]
            }
        ]
    });

    //实力一个Vue对象
    new Vue({
        el:"#app",
        router:router,
        components:{
            App
        },
        template: `<App></App>`
    })
</script>
</body>
</html>

2.6,VueRouter子路由的钩子函数

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="UTF-8">
    <title>钩子函数</title>
    <script src="vue.min.js"></script>
    <script src="vue-router.js"></script>
</head>
<body>

<div id="app">

</div>
<script>
    // 1,使用VueRouter使用路由
    Vue.use(VueRouter);

    let Home = {
        template:`
            <div>
                <h1>这是首页页面</h1>
            </div>
        `
    };
    //手写一个login页面的组件
    let Login = {
        template: `
            <div>
                <h1>这是登录页面</h1>
            </div>
        `
    };
    //支付的组件
    let Pay = {
        template:`
            <div>
                <h1>这是支付页面</h1>
            </div>
        `
    };

    // 把这些组件注册到App中
    let App = {
        // router-link会渲染成a标签, to会渲染成href
        // router-view是内容的渲染出口
        template:`
            <div>
                <router-link :to="{ name:'home' }">首页</router-link>
                <router-link :to="{ name:'login' }">登录</router-link>
                <router-link :to="{ name:'pay' }">支付</router-link>
                <router-view></router-view>
            </div>
        `
    };

    // 实例化一个router对象
    // 把a按标签的锚点值和页面内容绑定了对应关系
    let router = new VueRouter({
        routes:[
            {
                name:'home',
                path:'/',
                component:Home
            },
            {
                name:'login',
                path:'/login',
                component:Login,
            },
            {
                name:'pay',
                path:'/pay',
                component:Pay,
            }
        ]
    });
    // 通过router对象的beforeEach(function(to, from, next))
    router.beforeEach(function(to, from, next){
        console.log("to", to);
        console.log("from", from);
        console.log("next", next);
        if (to.meta.require_login){
            next('/login');
        }else {
            next();
        }
    });
    new Vue({
        el:"#app",
        template:'<App></App>',
        components:{
            App
        },
        // 在根实例中注册router对象
        router:router
    })
</script>
</body>
</html>

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转载自www.cnblogs.com/ljc-0923/p/10062878.html