Bootstrap模态框垂直高度居中问题

　　Bootstrap对话框改变其默认宽高，高度不会自适应居中。为解决这个问题，最好的方式是能够通过css来解决，试了几种网上的方案发现都不行。然后想到可以通过js来修正，什么时候修正最好？于是想到可以注册全局的事件。

　　下表是Bootstrap官方的事件。

Event Type	Description
show.bs.popover	This event fires immediately when the show instance method is called.
shown.bs.popover	This event is fired when the popover has been made visible to the user (will wait for CSS transitions to complete).
hide.bs.popover	This event is fired immediately when the hide instance method has been called.
hidden.bs.popover	This event is fired when the popover has finished being hidden from the user (will wait for CSS transitions to complete).
inserted.bs.popover	This event is fired after the show.bs.popover event when the popover template has been added to the DOM.

Copy

$('#myPopover').on('hidden.bs.popover', function () {
  // do something…
})

　　但是，我使用的是$(aa).modal('show')，所以改成这样：
　　

$(function () {
    //修正modal弹窗高度不能自适应的问题
    $('body .modal').on('show.bs.modal', function () {
        var $cur = $(this);
        $cur.css("top", ($(window).height() - $cur.height()) / 2);
    });
});