为什么v-bind:class绑定的md-show不能渲染
<div class="md-modal modal-msg md-modal-transition " v-bind:class="{'md-show' : true}" id="showModal" >
<div class="md-modal-inner">
<div class="md-top">
<button class="md-close">关闭</button>
</div>
<div class="md-content">
<div class="confirm-tips">
<p id="cusLanInfo">你确认删除此订单信息吗?</p>
</div>
<div class="btn-wrap col-2">
<button class="btn btn--m" id="btnModalConfirm">Yes</button>
<button class="btn btn--m btn--red" id="btnModalCancel">No</button>
</div>
</div>
</div>
</div>
