saveRelayRemark(index) {
    const remark = this.deviceInfo.thingsModels.find(item => item.id === `remark_ch${index}`);
    if (remark) {
        remark.value = this.relayRemarks[index];
        this.mqttPublish(this.deviceInfo, remark);
    }
},



<div class="relay-remark">
<el-input v-model="relayRemarks[4]" placeholder="添加备注" size="mini"
    @blur="saveRelayRemark(4)">
    <template slot="prepend">
        <i class="el-icon-edit"></i>
    </template>
</el-input>
</div>