1.首先放出结论,自定义验证规则必须降所有的可能全部都return callback出去,不然不会走validate
错误示范
// template
<el-form
      ref="ruleFormRef"
      :model="ruleForm"
      :rules="rules"
      label-width="120px"
      class="demo-ruleForm"
    >
      <el-form-item label="名字" prop="name">
        <el-input v-model="ruleForm.name" />
      </el-form-item>
      <el-form-item>
        <el-button type="primary" @click="submitForm">验证</el-button>
      </el-form-item>
    </el-form>
//script
import { reactive, ref } from "vue";
const ruleForm = reactive({
  name: "",
});
const nameChange = (rule, value, callback) => {
  if (!value) {
    return callback(new Error("请填写名字"));
  }
};
const rules = {
  name: [
    {
      validator: nameChange,
      trigger: "blur",
    },
  ],
};
const submitForm = async () => {
  ruleFormRef.value.validate((valid) => {
    if (valid) {
      alert("ok");
    } else {
      alert("no");
    }
  });
};
        2.效果如下


3.可以看到含有return callback的未填写情况是触发了ruleFormRef.value.validate,可以获取到valid的问题,但是填写了之后是不会走valid的,
4.将规则修改,使得填写之后的表单验证也有对应的return callback
const nameChange = (rule, value, callback) => {
  if (!value) {
    return callback(new Error("请填写名字"));
  } else {
    return callback();
  }
};
        5.这样的条件下就可以验证表单无问题时的valid
