javascript-vue-router始终创建一个新的Component实例

我在vue-router中发现了一个问题,这让我非常感动.
总是在我的路线之间切换时,会创建该组件的新实例.此外,旧实例不会被删除并在后台运行！

我希望当我打开一条路线时,旧组件将被破坏或停止运行.

有解决此问题的解决方法吗？

这是一个小提琴：https://jsfiddle.net/4xfa2f19/5885/

let foo = {
    template: '<div>Foo</div>',
    mounted() {
        console.log('Mount Foo with uid: ' + this._uid);
        setInterval(() => {console.log('Instance ' + this._uid + ' of Foo is running')}, 500);
    }
};

let bar = {
    template: '<div>Bar</div>',
    mounted() {
        console.log('Mount Bar with uid: ' + this._uid);
        setInterval(() => {console.log('Instance ' + this._uid + ' of Bar is running')}, 500);
    }
};


const router = new VueRouter({
    routes: [
        { path: '/user/foo', component: foo },
        { path: '/user/bar', component: bar }
    ]
});


const app = new Vue({ router }).$mount('#app');

解决方法:

有两种方法可以解决此问题：

正确清理销毁钩

如果使用任何外部事件侦听器,例如setInterval,addEventListener等,则还需要在销毁组件时注销它们,例如：

{
    name: '...',
    template: '...',
    data() {
        return {
            interval: undefined,
            timeout: undefined
        };
    },
    mounted() {
        interval = setInterval(() => {console.log('Instance ' + this._uid + ' of myself is running')}, 500);
        timeout = setTimeout(() => {console.log('Instance ' + this._uid + ' of myself is running')}, 500);
        document.addEventListener('click', this.onOutsideClick);
    },
    beforeDestroy() {
        // Cleanup interval
        clearInterval(interval);
        // Cleanup any pending timeouts
        clearTimeout(timeout);
        // Cleanup any event listeners outside the root of the element
        document.removeEventListener('click', this.onOutsideClick);
    },
    methods: {
        onOutsideClick() {
            ...
        }
    }
}

使用keep-alive使组件保持活动状态

使用keepalive时,Vue会缓存您的组件,并使其在后台保持活动状态,这意味着将仅存在一个实例.如果您有大量路由,这可能会消耗更多内存

<keep-alive>
    <router-view></router-view>
</keep-alive>

标签：vue-router,javascript,vue-js,routing
来源： https://codeday.me/bug/20191011/1895429.html