## 1. 线上不支持使用 `const {ctx} = getCurrentInstance()` 解决方案: const {proxy} = getCurrentInstance() 但是不建议 ## 2. 获取组件实例 类似于vue2.x ref="stage" 获取stage实例 解决方案: ```vue // template <div ref="refStage"></div> // script setup() { const refStage = ref(null) return { refStage } } ``` ## 3. 自定义指令 使用指令的组件实例时 失去响应性 ```javscript // instance <template> <div v-directive></div> </template> export default { setup() { const list = inject('list', []) return { list } } } // v-directive const instance = null const mousedownHandle = () => { console.log(instance.list.length) } export default { onmount(el, binding) { instace = binding.instance $(el).on('mousedown', mousedownHandle) } } // instance.list.length 一直等于0, 即使instance发生变化 依然是0 ``` 解决方案: ```javascript const mousedownHandle = () => { console.log(instance.list.length) } export default { onmount(el, binding) { const instace = binding.instance $(el).on('mousedown', {instace}, mousedownHandle) } } ```