默认数据是这样，如果更改了其中一个，文本框变成红色

<el-form-item label="Activity name">
        <el-input
          v-model="form.name"
          v-highlight="datas['name']"
          @input="changeValue('name')"
        />
      </el-form-item>
      <el-form-item label="Activity zone">
        <el-select
          v-model="form.region"
          v-highlight="datas['region']"
          placeholder="please select your zone"
          @change="changeValue('region')"
        >
          <el-option label="Zone one" value="shanghai" />
          <el-option label="Zone two" value="beijing" />
        </el-select>
      </el-form-item>

 v-highlight="datas['name']"

@input="changeValue('name')"

需要改变的item加入这2句话

import Vue from "vue";
Vue.directive("highlight", {
  update: function (el, binding) {
    const classname = el.getAttribute("class");
    const elRef =
      classname == "el-input" ? el.children[0] : el.children[0].children[0];
    if (binding.value !== binding.oldValue) {
      elRef.style.color = binding.value ? "red" : "";
    }
  },
});

 el.children[0] :和el.children[0].children[0]主要目的是找到input的元素，

数据：

form: {

        name: "666",

        region: "shanghai",

      },

      datas: { name: false, region: false },

 changeValue(key) {

      this.datas[key] = true;

    },

 讲当前更改的数据变成true即可