直接上代码

在setup中使用绑定的ref

import { defineComponent, ref, onMounted } from 'vue'
import { ElRadioGroup, ElRadio,RadioInstance } from 'element-plus'
import CustomComponent from '@/components/CustomComponent' //自定义组件
export default defineComponent({
  setup() {
    const chartRef = ref<HTMLDivElement | null>()//可以绑定为div或者任意组件
    const radioRef = ref<RadioInstance>() //elradio的ref
    const customComponentoRef = ref<InstanceType<typeof CustomComponent>>() //自定义组件的ref 写法，通过ref.value.xxx调用子组件方式时，子组件中一定要把xxx这个方法return出来
    
    onMounted(() => {
      console.log(chartRef.value) // Element div...
    })

     return () => <div ref={chartRef} style="{{width: 200px, height: 100px}}"></div>
  },
})

在render 函数中使用

需要先在setup中return出来

import { defineComponent, ref, onMounted } from 'vue'
import { ElRadioGroup, ElRadio,RadioInstance } from 'element-plus'
import CustomComponent from '@/components/CustomComponent' //自定义组件
export default defineComponent({
  setup() {
    const chartRef = ref<HTMLDivElement | null>()//可以绑定为div或者任意组件
    const radioRef = ref<RadioInstance>() //elradio的ref
    const customComponentoRef = ref<InstanceType<typeof CustomComponent>>() //自定义组件的ref 写法，通过ref.value.xxx调用子组件方式时，子组件中一定要把xxx这个方法return出来
    
    onMounted(() => {
      console.log(chartRef.value) // Element div...
    })

    return {
      chartRef
    }
  },
  render() {
    return <div ref={el => this.chartRef = el} style="{{width: 200px, height: 100px}}"></div>
  }
})