需要引入jquery和bootstrap相关包，然后把下面的代码复制进去就可以了：
<div class="modal fade" id="loadingModal" backdrop="static" keyboard="false">
<div style="width: 200px;height:20px; z-index: 20000; position: absolute; text-align: center; left: 50%; top: 50%;margin-left:-100px;margin-top:-10px">
<div class="progress progress-striped active" style="margin-bottom: 0;">
<div class="progress-bar" style="width: 100%;"></div>
</div>
<h5>loading...</h5>
</div>
</div>
<script>
showLoading = function(){
$('#loadingModal').modal({backdrop: 'static', keyboard: false});
}
hideLoading = function(){
$('#loadingModal').modal('hide');
}
</script>