js 面向对象打气球小游戏

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
    <style>
        * {
            margin:0;
            padding:0;
        }
        
        html，body {
            height:100%;
            background-color:#ccc;
        } 
        
        div {
            width:250px;
            height:333px;
            position:absolute;
            background: url(img/ballons.png) no-repeat 0px 0;
        }
    </style>
</head>
    
<body>
    <!--<div></div>-->
    <h2></h2>
    <h2></h2>
    <script>
        var balloons = [];
        var allScore = 0;
        /*面向对象创建气球的构造函数*/
        function Balloon(){
            this.dom = null;
            this.x = 0;
            this.y = 0;        
            this.score = 0;
            this.init();
            balloons.push(this);
            this.bindEvent();
        }
        
        Balloon.prototype.init = function(){
            this.dom = document.createElement('div');
            document.body.appendChild(this.dom);
            this.x = parseInt(Math.random()*(document.documentElement.clientWidth-250));
            this.y = document.documentElement.clientHeight;
            this.score = parseInt(Math.random()*12)+1; //[1~13);
            this.dom.style.left = this.x+"px";
            this.dom.style.top = this.y+"px";
            var curX = -((this.score-1)%4)*250;
            var curY = -parseInt(((this.score-1)/4))*333;
            this.dom.style.backgroundPosition = curX+"px "+curY+"px";
            
            /*
                1   2   3    4        (0 -250 -250*2 250*3) 0
                5   6   7    8        (0 -250 -250*2 250*3) -333
                9  10  11   12         (0 -250 -250*2 250*3) -333*2
            
            */
        };
        
        Balloon.prototype.bindEvent = function(){
            var _this = this;
            this.dom.onclick = function(){
                /*每次点击计算分数，下树，从数组中下线*/
                allScore += _this.score;
                _this.goDied();
            };
        }
        
        Balloon.prototype.update = function(){
            this.y -= this.score*3;
            if(this.y < -333){
                this.goDied();
            }
            this.dom.style.top = this.y+"px";
        };
        
        Balloon.prototype.goDied = function(){
            document.body.removeChild(this.dom);
            for(var i=0;i<balloons.length;i++){
                if(balloons[i] == this){
                    balloons.splice(i,1);
                }
            }
        };
        
        var allTime = 20;
        var iframe = 0;
        /*给new 出来的每一个this对象添加对应的属性
            每秒创建4个气球 */
        var timer = setInterval(function(){
            iframe++;
            if(iframe %10 == 0){
                allTime--;
                for(var i=0;i<4;i++){
                    new Balloon();
                }
            }
            
            for(var i=0;i<balloons.length;i++){
                balloons[i]&&balloons[i].update();
            }
            document.getElementsByTagName('h2')[0].innerHTML = "你剩余的时间为："+allTime+"秒";
            document.getElementsByTagName('h2')[1].innerHTML = "你目前的分数："+allScore+"分";
            if(!allTime){
                alert("Game over ，你的总分数为："+allScore+"分");
                clearInterval(timer);
            }
        },100);
        
        
        
    </script>
</body>
</html>

图片见文件中
js 面向对象 打气球小游戏

js 面向对象打气球小游戏
