header.vue（右上角）
 

<template>
    <div class="header">
        <!-- 折叠按钮 -->
        <div class="collapse-btn" @click="collapseChage">
            <i v-if="!collapse" class="el-icon-s-fold"></i>
            <i v-else class="el-icon-s-unfold"></i>
        </div>
        <div class="logo">在线考试管理系统</div>
        <div class="header-right">
            <div class="header-user-con">
                <!-- 全屏显示 -->
                <div class="btn-fullscreen" @click="handleFullScreen">
                    <el-tooltip effect="dark" :content="fullscreen?`取消全屏`:`全屏`" placement="bottom">
                        <i class="el-icon-rank"></i>
                    </el-tooltip>
                </div>
                <!-- 用户头像 -->
                <div class="user-avator">
                    <img :src="getAvatar(form.avatar)" alt="User Avatar">
                </div>
                <!-- 用户名下拉菜单 -->
                <el-dropdown class="user-name" trigger="click" @command="handleCommand">
                    <span class="el-dropdown-link">
                        {
  {username}}
                        <i class="el-icon-caret-bottom"></i>
                    </span>
                    <el-dropdown-menu slot="dropdown">
                        <!-- <el-dropdown-item command="updatePassword">个人中心</el-dropdown-item> 与下面的效果一致-->
                        <el-button style="border: 0;" @click="openDialog2">个人中心</el-button><br>
                        <el-button style="border: 0;" @click="openDialog">待办事件</el-button>
                        <el-dropdown-item command="loginout">退出登录</el-dropdown-item>
                    </el-dropdown-menu>
                </el-dropdown>
            </div>
        </div>
        <el-dialog title="个人中心" :modal="false"  :visible.sync="addVisible" width="47%" style="height: auto;margin-left: 238px;margin-top: 60px;" :before-close="clearAddForm">
            <el-form label-position="left"  ref="addForm" label-width="80px"  :model="form" >
                <el-form-item label="用户名" style="margin-left: 30%;margin-top: 25px;">
                    <el-input v-model="form.userName" style="width: 45%;"></el-input>
                </el-form-item>
                <el-form-item label="密码" style="mar