代码如下: (function($){ $.fn.center = function(){ var top = ($(window).height() - this.height())/2; var left = ($(window).width() - this.width())/2; var scrollTop = $(document).scrollTop(); var scrollLeft = $(document).scrollLeft(); return this.css( { position : 'absolute', 'top' : top + scrollTop, left : left + scrollLeft } ).show(); } })(jQuery)