Modal.DEFAULTS = {
 backdrop: true,
 keyboard: true,
 show: true
}
//新加入的拖拽
Modal.prototype.draggable = function () {
 var $ele = this.$element;
 var mouseOffset;
 var $modalDialog = $ele.find(".modal-dialog");
 var dialogOffset;

 $ele.find(".modal-header").on('mousedown', function (event) {
 $(this).addClass({cursor: 'move'});
 $('body').addClass('select');
 dialogOffset = $modalDialog.offset();
 mouseOffset = {
 top: event.pageY - dialogOffset.top,
 left: event.pageX - dialogOffset.left
 };
 $('body').on("mousemove", function (event) {
 var left = event.pageX - mouseOffset.left;
 var top = event.pageY - mouseOffset.top;
 if (left < 10) {
 left = 0;
 } else if (left > $(window).width() - $modalDialog.width()) {
 left = $(window).width() - $modalDialog.width();
 }
 if (top < 10) {
 top = 0;
 } else if (top > $(window).height() - $modalDialog.height()) {
 top = $(window).height() - $modalDialog.height();
 }
 $modalDialog.offset({
 top: top,
 left: left
 });
 });
 });

 $(document).on("mouseup mouseleave", function () {
 $('body').off("mousemove");
 });
}

Modal.prototype.show = function (_relatedTarget) {
 var that = this
 var e = $.Event('show.bs.modal', {relatedTarget: _relatedTarget})

 this.$element.trigger(e)

 if (this.isShown || e.isDefaultPrevented()) return

 this.isShown = true

 //調用draggable()增加拖拽
 this.draggable()
 this.checkScrollbar()
 this.setScrollbar()
 this.$body.addClass('modal-open')

 this.escape()
 this.resize()
 //......省略
}