* {    padding: 0px;    margin: 0px;}body {    overflow: hidden;}#dbird {    position: absolute;    width: 206px;    height: 121px;}.direction-37 {    transform: rotateY(180deg);}.direction-38 {    transform: rotate(-60deg);}.direction-40 {    transform: rotate(60deg);}

/// <reference path="jquery-1.10.2.min.js" />$(function () {    var bird = $("#dbird");//获取到了小鸟的对象    var off = bird.offset();//获取到小鸟的方位的对象    var icount = 10;//小鸟一次移动的位置    var keyrecord = 39;    var birdSize = { width: bird.width(), height: bird.height() };//获取到小鸟的大小    var docSize = { width: $(window).width(), height: $(window).height() };//获取到当前浏览器的高度和宽度    $(document).keydown(function (event) {//对网页按下键盘的键的时候触发一个事件，event事件源        var code = event.keyCode;//获取事件源的编码        if (keyrecord != code) {            bird.removeClass().addClass(‘direction-‘ + code)        }        keyrecord = code;        switch (code) {            case 37://左键                off.left -= icount;                if (off.left < -birdSize.width) {                    off.left = docSize.width;                }                break;            case 38://上键                off.top -= icount;                if (off.top < -birdSize.height) {                    off.top = docSize.height;                }                break;            case 39://右键                off.left += icount;                if (off.left > docSize.width) {//当小鸟移动到浏览器的最右边的时候，让它回到浏览器的最左边                    off.left = -birdSize.width;                }                break;            case 40://下键                off.top += icount;                if (off.top > docSize.height) {                    off.top = -birdSize.height;                }                break;        }        bird.offset(off);//设置小鸟新的方位值    });});