1Jing ElementUI wants to customize the header, which is officially done like this
<el-table :data="tableData" stripe border highlight-current-row class="drag_table" style="width: 100%;margin-top:20px;">
<el-table-column v-for="(item, index) of tableHeader" :prop="item" :label="item" :key="index"
:column-key="index.toString()" >
<template slot="header" slot-scope="slot">
{{ slot }}
</template>
</el-table-column>
</el-table>
what I want to ask is, how do I get the injected value, for example, how to implement the original header lable, that I want to define is xx+?