Bootstrap modal 模态框垂直居中显示补丁

<script>
    $.fn.modal.Constructor.prototype.adjustDialog1 = function(){
var modalIsOverflowing = this.$element[0].scrollHeight > document.documentElement.clientHeight;
        this.$element.css({
            paddingLeft:  !this.bodyIsOverflowing && modalIsOverflowing ? this.scrollbarWidth : '',
            paddingRight: this.bodyIsOverflowing && !modalIsOverflowing ? this.scrollbarWidth : ''
        });
/**设置弹出框垂直居中start**/
        var $modal_dialog = $(this.$element[0]).find('.modal-dialog');
        // 获取可视窗口的高度
        // var clientHeight = (document.body.clientHeight > document.documentElement.clientHeight) ? document.body.clientHeight: document.documentElement.clientHeight;
        // 得到dialog的高度
        var dialogHeight = $modal_dialog.height();
        //计算出距离顶部的高度
        var m_top = (document.documentElement.clientHeight - dialogHeight)/2;
        $modal_dialog.css({'margin':m_top + 'px auto'});
        /**设置弹出框垂直居中end**/
    }
</script>

红色部分为我们的处理逻辑，绿色部分为Bootstrap原生的处理函数，直接拷贝：

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

via：https://blog.csdn.net/yucaifu1989/article/details/51425424