bootstrap modal模态框垂直居中

直接修改bootstrap.js 源码：

弹出框出现时， 调用的是 Modal.prototype.show() 方法， 而show 方法中又调用了that.adjustDialog() 方法：

Modal.prototype.adjustDialog = function () {var modalIsOverflowing = this.$element[0].scrollHeight > document.documentElement.clientHeightthis.$element.css({paddingLeft: !this.bodyIsOverflowing && modalIsOverflowing ? this.scrollbarWidth : '',paddingRight: this.bodyIsOverflowing && !modalIsOverflowing ? this.scrollbarWidth : ''})}

修改：

Modal.prototype.adjustDialog = function () {var modalIsOverflowing = this.$element[0].scrollHeight > document.documentElement.clientHeightthis.$element.css({paddingLeft: !this.bodyIsOverflowing && modalIsOverflowing ? this.scrollbarWidth : '',paddingRight: this.bodyIsOverflowing && !modalIsOverflowing ? this.scrollbarWidth : ''})var $modal_dialog = $(this.$element[0]).find('.modal-dialog');var m_top = ( $(window).height() - $modal_dialog.height() )/2;$modal_dialog.css({'margin': m_top + 'px auto'});}