常见示例
最常见的多标签过渡是一个列表和描述这个列表为空消息的元素：
<transition> <table v-if="items.length > 0"> <!-- ... --> </table> <p v-else>Sorry, no items found.</p> </transition>
下面是一个例子
<style>
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition:opacity .5s;}
</style>
<div id="demo">
<button @click="clear">清空数据</button>
<button @click="reset">重置</button>
<transition name="fade">
<ul v-if="items.length > 0">
<li v-for="item in items">{{item}}</li>
</ul>
<p v-else>Sorry, no items found.</p>
</transition>
</div>
<script>
new Vue({
el: '#demo',
data: {
items: ['html','css','js']
},
methods:{
clear(){
this.items.splice(0);
},
reset(){
history.go();
}
}
})
</script>
同标签名称
如果是相同标签名的元素切换时，Vue 为了效率只会替换相同标签内部的内容
<style>
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition:opacity .5s;}
</style>
<div id="demo">
<button @click="show = !show">toggle</button>
<transition name="fade">
<p v-if="show">Jb51</p>
<p v-else>JB51</p>
</transition>
</div>
<script>
new Vue({
el: '#demo',
data: {
show:true
},
})
</script>
由下面的示例可知，两个相同的p元素切换时，无过渡效果
因此，对于具有相同标签名的元素切换的情况，需要通过 key 特性设置唯一的值来标记以让 Vue 区分它们
<div id="demo"> <button @click="show = !show">toggle</button> <transition name="fade"> <p v-if="show" key="trueMatch">Jb51</p> <p v-else key="falseMatch">JB51</p> </transition> </div>
替代if
在一些场景中，可以给通过给同一个元素的 key 特性设置不同的状态来代替 v-if 和 v-else
<transition> <button v-if="isEditing" key="save">Save</button> <button v-else key="edit">Edit</button> </transition>
上面的例子可以重写为
<transition>
<button v-bind:key="isEditing">
{{ isEditing "htmlcode">
<style>
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition:opacity .5s;}
</style>
<div id="demo">
<button @click="isEditing = !isEditing">toggle</button>
<transition name="fade">
<p v-bind:key="isEditing">
{{ isEditing "htmlcode">
<transition>
<button v-if="docState === 'saved'" key="saved">Edit</button>
<button v-if="docState === 'edited'" key="edited">Save</button>
<button v-if="docState === 'editing'" key="editing">Cancel</button>
</transition>
可以重写为
<transition>
<button v-bind:key="docState">{{ buttonMessage }}</button>
</transition>
computed: {
buttonMessage: function () {
switch (this.docState) {
case 'saved': return 'Edit'
case 'edited': return 'Save'
case 'editing': return 'Cancel'
}
}
}
下面是一个例子
<style>
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition:opacity .5s;}
</style>
<div id="demo">
<button @click="change">change</button>
<transition name="fade">
<p v-bind:key="docState">{{ message }}</p>
</transition>
</div>
<script>
new Vue({
el: '#demo',
data: {
index:0,
isEditing:true,
arr:['saved','edited','editing']
},
computed: {
docState(){
return this.arr[this.index];
},
message() {
switch (this.docState) {
case 'saved': return 'Edit'
case 'edited': return 'Save'
case 'editing': return 'Cancel'
}
}
},
methods:{
change(){
this.index = (++this.index)%3;
}
}
})
</script>
过渡模式
先看下面这个例子
<style>
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition:opacity .5s;}
</style>
<div id="demo">
<transition name="fade">
<button :key="isOn" @click="isOn = !isOn">{{ isOn "htmlcode">
<div id="demo">
<transition name="fade" mode="in-out">
<button :key="isOn" @click="isOn = !isOn">{{ isOn "htmlcode">
<div id="demo">
<transition name="fade" mode="out-in">
<button :key="isOn" @click="isOn = !isOn">{{ isOn "htmlcode">
<style>
#demo{position:relative;}
#demo button{position:absolute;left:40px;}
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition: 1s;}
</style>
<div id="demo">
<transition name="fade" >
<button :key="isOn" @click="isOn = !isOn">{{ isOn "htmlcode">
<style>
#demo{position:relative;}
#demo button{position:absolute;left:40px;}
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter{transform:translateX(30px);}
.fade-leave-to{transform:translateX(-30px);}
.fade-enter-active,.fade-leave-active{transition: 1s;}
</style>
如果设置in-out模式，将实现更酷的滑动效果
<style>
#demo{position:relative;}
#demo button{position:absolute;left:40px;}
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter{transform:translateX(30px);}
.fade-leave-to{transform:translateX(-30px);}
.fade-enter-active,.fade-leave-active{transition: 1s;}
</style>
<div id="demo">
<transition name="fade" mode="in-out">
<button :key="isOn" @click="isOn = !isOn">{{ isOn "htmlcode">
<style>
.fade-enter,.fade-leave-to{opacity:0;}
.fade-enter-active,.fade-leave-active{transition: .5s;}
</style>
<div id="example">
<button @click="change">切换页面</button>
<transition name="fade" mode="out-in">
<component :is="currentView"></component>
</transition>
</div>
<script>
new Vue({
el: '#example',
data:{
index:0,
arr:[
{template:`<div>ComponentA</div>`},
{template:`<div>ComponentB</div>`},
{template:`<div>ComponentC</div>`}
],
},
computed:{
currentView(){
return this.arr[this.index];
}
},
methods:{
change(){
this.index = (++this.index)%3;
}
}
})
更多关于Vue过渡动画的文章大家可以查看下面的相关链接