flytalk/static/html/mail_left.html

<el-menu
        :default-active="fid">
    <el-menu-item  v-on:click="openUrl('/write')">
        <i class="el-icon-edit"></i>
        <span slot="title">写信</span>
    </el-menu-item>
    <el-menu-item :index="v" v-for="(f,v) in folders" v-bind:key="v"  v-on:click="openUrl('/list?fid='+v)">
        <i class="el-icon-menu"></i>
        <span slot="title"><{v}></span>
    </el-menu-item>
</el-menu>