Vue3渲染器与渲染函数的用法详解

import { h } from 'vue'

export default {
  render() {
    return h(
      'div', 
      { class: 'container', id: 'app' },
      [
        h('h1', { style: { color: 'blue' } }, '标题'),
        this.showSubtitle ? 
          h('p', null, '动态子标题') : 
          h('div', { class: 'placeholder' }),
        h('ul', null, 
          this.items.map(item => 
            h('li', { key: item.id }, item.text)
          )
        )
      ]
    )
  }
}

import { createRenderer } from 'vue'

const { createApp } = createRenderer({
  createElement(type) {
    console.log(`创建元素: ${type}`)
    return { type }
  },
  
  insert(el, parent) {
    console.log(`插入 ${el.type} 到 ${parent.type}`)
  },
  
  patchProp(el, key, prevValue, nextValue) {
    console.log(`更新属性: ${key} = ${nextValue}`)
  }
})

const app = createApp({
  render() {
    return h('div', { id: 'app' }, [
      h('span', { class: 'text' }, '自定义渲染')
    ])
  }
})

app.mount({ type: 'root' })

import { shallowRef } from 'vue'

const heavyList = shallowRef([...]) // 浅层响应

h('div', { key: item.id }, item.content)

return h(Fragment, null, [
  h('header', ...),
  h('main', ...),
  h('footer', ...)
])

const staticContent = h('div', { class: 'static' }, '不变的内容')

render() {
  return h('div', [
    staticContent,
    // ...动态内容
  ])
}

function createDynamicComponent(type, props) {
  return h(type, {
    ...props,
    onCustomEvent: handleEvent
  })
}

import { ref, h } from 'vue'

export default {
  setup() {
    const count = ref(0)
    
    return () => h('div', [
      h('button', {
        onClick: () => count.value++
      }, '增加'),
      h('span', `当前计数: ${count.value}`)
    ])
  }
}