封装动画让代码可复用

如下是一个简单的点击渐变、渐隐:

<!DOCTYPE html><html><head>    <title></title>    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />    <link rel="stylesheet" type="text/css" href="./animate.css">    <script src="./vue.js"></script>    <!-- <script src="http://cdn.staticfile.org/vue/2.6.10/vue.common.dev.js"></script> -->    <style type="text/css">        /*因为没有给它命名,所以用默认v开头的class名*/        .v-enter, .v-leave-to {            opacity: 0;        }        .v-enter-active, .v-leave-active {            transition: opacity 1s;        }    </style></head><body>    <div id="root">        //性能考虑,尽量不用index作为key值 <br>        <transition>            <div v-show="show">hello</div>        </transition>        <button @click="handBtnClick">toggle</button>    </div>    <script type="text/javascript">        var vm = new Vue({            el: "#root",            data: {                show: true            },            methods: {                handBtnClick: function() {                    this.show = !this.show                }            }        });    </script></body></html>

封装后:

<!DOCTYPE html><html><head>    <title></title>    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />    <link rel="stylesheet" type="text/css" href="./animate.css">    <script src="./vue.js"></script>    <!-- <script src="http://cdn.staticfile.org/vue/2.6.10/vue.common.dev.js"></script> -->    <style type="text/css">        /*因为没有给它命名,所以用默认v开头的class名*/        .v-enter, .v-leave-to {            opacity: 0;        }        .v-enter-active, .v-leave-active {            transition: opacity 1s;        }    </style></head><body>    <div id="root">        <fade :show="show">            <div>hello world</div>        </fade>        <fade :show="show">            <h2>hello world</h2>        </fade>        <button @click="handBtnClick">toggle</button>    </div>    <script type="text/javascript">        Vue.component("fade", {            props: ["show"],            template: `                <transition>                    <slot v-if="show"></slot>                </transition>            `        });        var vm = new Vue({            el: "#root",            data: {                show: true            },            methods: {                handBtnClick: function() {                    this.show = !this.show                }            }        });    </script></body></html>

其实css也可以封装:可以不用css动画,而用js动画:

<!DOCTYPE html><html><head>    <title></title>    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />    <link rel="stylesheet" type="text/css" href="./animate.css">    <script src="./vue.js"></script>    <!-- <script src="http://cdn.staticfile.org/vue/2.6.10/vue.common.dev.js"></script> -->    <style type="text/css">        /*因为没有给它命名,所以用默认v开头的class名*/        .v-enter, .v-leave-to {            opacity: 0;        }        .v-enter-active, .v-leave-active {            transition: opacity 1s;        }    </style></head><body>    <div id="root">        <fade :show="show">            <div>hello world</div>        </fade>        <fade :show="show">            <h2>hello world</h2>        </fade>        <button @click="handBtnClick">toggle</button>    </div>    <script type="text/javascript">        Vue.component("fade", {            props: ["show"],            template: `                <transition @before-enter="handleBeforeEnter" @enter="handleEnter">                    <slot v-if="show"></slot>                </transition>            `,            methods: {                handleBeforeEnter: function(el) {                    el.style.color = "red"                },                handleEnter: function(el, done) {                    setTimeout(()=>{                        el.style.color = "green"                        done() //再次注意:要记得done()                    }, 1000)                }            }        });        var vm = new Vue({            el: "#root",            data: {                show: true            },            methods: {                handBtnClick: function() {                    this.show = !this.show                }            }        });    </script></body></html>

(这种封装可以完整的将css、js、html都封装在一个组件中。推荐)