vue淡入淡出

<button @click="show=!show">点击</button>
<transition name="fade">
    <div v-show='show' >动画实例</div>
</transition>

.fade-enter-active,
.fade-leave-active
{
    transition:opcity 2s;
}

.fade-enter,
.fade-leave-to
{
    opacity:0;
}

.fade-enter-to,
.fade-leave
{
    opacity:1;
}