Element UI表单中数组循环验证必填方法

表单内有部分数据是通过数组循环展示出来的，需要对循环出来的表单进行验证，方式如下：

<div class="material-list" v-for="(item,index) in model.materialList" :key="index">
    <el-form-item label="类型" :prop="`materialList.${index}.materialType`" :rules="{ required: true, message: '请选择类型',trigger: 'change'}">
        <el-select v-model="item.materialType" placeholder="请选择类型" style="width:230px" @change="Change" :remote-method="remoteMethodmaterialType" filterable remote>
               <el-option 
                   v-for="(item,index) in materialTypeList"
                   :key="index"
                   :label="item"
                   :value="item">
                </el-option>
         </el-select>
   </el-form-item>
</div>

解析：首先循环model里边的数组materialList，然后在el-form-item标签的prop验证中添加验证的字段为materialList数组下的字段名（通过index索引来获取）

数据格式，如下：

data(){
    return{
        model: {
                billId: '',picker: '',remark: '',
                materialList: [
                    {materialType: '',brand:'',material: '',unit:'',specificationModel:'',materialId: '',actualNumber:''},
                ]
            },
    }