点击增加后会新增一行，点击每行后面的删除图标则会删除该行，新增按钮只会出现在最后一行
```
<el-col :span="12" class="mb20">
<el-form-item
:label="index == 0 ? '选择原材料' : ''"
v-for="(item, index) in form.productItemList"
:key="index"
:prop="'domains.' index '.value'"
>
<el-select v-model="item.name" filterable clearable placeholder="请输入原材料" @change="changeValue" @clear="clearValue">
<el-option v-for="item in productAll" :key="item.value" :label="item.name" :value="item.id" />
</el-select>
<el-input v-model="item.num" placeholder="请输入数量" style="position: absolute; left: 300px; width: 160px"></el-input>
<el-button
v-if="index !== 0"
class="mt-2"
type="danger"
style="position: absolute; left: 545px; bottom: 0px"
@click.prevent="removeDomain(domain)"
>删除</el-button
>
</el-form-item>
<el-form-item>
<el-button @click="addDomain" type="primary" style="position: absolute; left: 475px; bottom: 18px">添加</el-button>
</el-form-item>
</el-col>
```
定义方法
```
// 添加原材料
const addDomain = () => {
form.productItemList.push({
name: '',
num: '',
});
};
// 删除原材料
const removeDomain = (item: any) => {
const index = form.productItemList.indexOf(item);
if (index === -1) {
form.productItemList.splice(index, 1);
}
};
```
定义表单提交数据
```
// 提交表单数据
const form = reactive({
productItemList: [
{
name: '',
num: '',
},
],
});
```
