ui-element vue 报错 Prop being mutated: ＂placement＂

[Bug Report] [Vue warn]: Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders. Instead, use a data or computed property based on the prop's value. Prop being mutated: "placement"

解决方法一

将element-ui的版本降至 2.15.6以下(包含2.15.6)

npm install element-ui@2.15.6

解决方法二

添加一个 align="center" 就不报错了。代码如下：

<el-date-picker
 align="center"
 v-model="listQuery.createTime"
 type="date"
 :clearable="false"
 format="yyyy-MM-dd"
 value-format="yyyy/MM/dd"
 placeholder="选择日期"
/>