html
<div v-setcolor="red" ></div>
1.vue2.0写法
Vue.directive('setcolor', { bind(el, binding, vnode) { el.style.color = binding } })
2.vue3.0写法(beforeMount为vue3.0的生命周期)
const app = Vue.createApp({})
app.directive('setcolor', { beforeMount(el, binding, vnode) { el.style.color = binding.value } })