Vue3 ts 获取 element-plus 组件 ref 实例，class component 模式

在 vue3 中获取组件的类型：

type EleForm = InstanceType<typeof ElForm>

获取 ElForm ref

<template>
    <el-form :model="form" ref="forms" :rules="rules"></el-form>
</template>

<script lang="ts">
import { Options, Vue } from 'vue-class-component';
@Options({})
export default class Main extends Vue {
    private forms: InstanceType<typeof ElForm>;
    mounted() {
      this.forms.validate((valid: boolean) => {
            console.log(valid)
        })
    }
}
</script>