el-form表单新增表单项动态校验；el-form校验动态表单v-if不生效；

场景：本文是两种表单校验
1.对于数组for循环，校验每一项
2.对于两个不同的字段，分别v-if显示隐藏的校验

一、新增和删除表单项，动态校验。

el-form表单动态动态新增表单进行校验。直接参考动态增减表单项

以下代码可直接复制：重点在于:prop :rules :key

<template><div><el-form :model="dynamicValidateForm" ref="dynamicValidateForm" label-width="110px" class="demo-dynamic"><div class="bor_box" v-for="(domain, index) in dynamicValidateForm.premiumList" :key="domain.key"><el-col :span="24"><div class="box4_div"><el-col :span="5"><el-form-item label="保费：" :prop="'premiumList.' + index + '.premium'" :rules="{required: true, message: '保费不能为空', trigger: 'blur'}"><el-input class="num_input" placeholder="请输入" v-model="domain.premium"></el-input></el-form-item></el-col><el-col :span="5"><el-form-item label="保费率：" :prop="'premiumList.' + index + '.rate'" :rules="{required: true, message: '保费率不能为空', trigger: 'blur'}"><el-input class="num_input" placeholder="请输入" :precision="2" :step="0.01" v-model="domain.rate"></el-input></el-form-item></el-col><el-col :span="5"><el-form-item label="上游费用率：" :prop="'premiumList.' + index + '.feeRate'" :rules="{required: true, message: '上游费用率不能为空', trigger: 'blur'}"><el-input class="num_input" placeholder="请输入" :max="100" v-model="domain.feeRate"></el-input></el-form-item></el-col><el-col :span="5"><el-form-item label="上游费用额：" :prop="'premiumList.' + index + '.fee'" :rules="{required: true, message: '上游费用额不能为空', trigger: 'blur'}"><el-input class="num_input" placeholder="请输入" v-model="domain.fee"></el-input></el-form-item></el-col><el-col :span="4"><el-button @click.prevent="removeDomain(domain,index)">删除</el-button></el-col></div></el-col></div><div><el-form-item><el-button type="primary" @click="submitForm('dynamicValidateForm')">提交</el-button><el-button @click="addDomain">添加保费</el-button><el-button @click="resetForm('dynamicValidateForm')">重置</el-button></el-form-item></div></el-form></div>
</template><script>
export default {data () {return {dynamicValidateForm: {premiumList: [{selected: 'Y', premium: undefined, rate: undefined, feeRate: undefined, fee: undefined, baofei1_unit: '', shangyoufeiyonge_unit: '', downRate: undefined, downFee: undefined, xiayoufeiyonge_unit: '',}],},}},created () {},methods: {submitForm (formName) {this.$refs[formName].validate((valid) => {if (valid) {alert('submit!')} else {console.log('error submit!!')return false}})},resetForm (formName) {this.$refs[formName].resetFields()},removeDomain (item, index) {if (index !== 0) {this.dynamicValidateForm.premiumList.splice(index, 1)}},addDomain () {this.dynamicValidateForm.premiumList.push({selected: 'N', premium: undefined, rate: undefined, feeRate: undefined, fee: undefined, baofei1_unit: '', shangyoufeiyonge_unit: '', downRate: undefined, downFee: undefined, xiayoufeiyonge_unit: '',key: Date.now()})},},
}
</script><style lang="less" scoped>
.bor_box {margin-left: 50px;margin-bottom: 10px;overflow: hidden;
}
</style>

二、el-form表单校验v-if不生效、el-form表单校验v-show不生效：

例如有个表单项，通过控制显示两个不同的表单项内容，分别需要校验对应的表单项即可。
如果是直接用v-if，会发现切换时候，校验不生效；
如果直接使用v-show，又发现即使不切换，隐藏了另外的表单项，也会触发校验规则。
正确做法是：使用v-if控制表单项的显示隐藏，同时需要给el-form-item加上自己的 prop=" " 和 key=" " ，这样才能区分。当然:rules 也要有自己对应的提示。

    <template v-if="flag"><el-form-item label="姓名：" prop="name" key="name" :rules="rules.name"><el-input v-model="formData.name" placeholder=""></el-input></el-form-item></template><template v-else><el-form-item label="退回原因：" prop="desc" key="desc" :rules="rules.desc"><el-input type="textarea" maxlength="500" show-word-limit v-model="formData.desc" placeholder="请填写退回原因"></el-input></el-form-item></template>