elementUI

<el-button style="font-size:16px"  type="text" @click="toggleSearchStatus = !toggleSearchStatus">{{ toggleSearchStatus ? '收起' : '展开' }} <i :class="toggleSearchStatus ? 'el-icon-arrow-up' : 'el-icon-arrow-down'"></i>
</el-button>

elementUI

<el-button style="font-size:16px"  type="text" @click="toggleSearchStatus = !toggleSearchStatus">{{ toggleSearchStatus ? '收起' : '展开' }} <i :class="toggleSearchStatus ? 'el-icon-arrow-up' : 'el-icon-arrow-down'"></i>
</el-button>