data-dismiss是bootstrap里自定義的屬性翻伺，給一個元素data-dimiss屬性的話材泄，可以通過點擊該元素達到讓目標消失的效果。
例如：當點擊按鈕時吨岭，直接關(guān)閉外層alert
<div class="alert alert-warning alert-dismissible" role="alert1">
<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button>
<strong>Warning!</strong> Better check yourself, you're not looking too good.
</div>
