<!DOCTYPE html><html> <head> <meta charset="utf-8"> <meta name="viewport" content="initial-scale=1.0, maximum-scale=1.0, user-scalable=no" /> <title>demo</title> <script src="http://cdn.bootcss.com/jquery/2.1.4/jquery.min.js"></script> <style type="text/css"> *{ padding: 0; margin: 0; list-style: none; } body{ background: #df412b; position: relative; } .banner1{ display: block; width: 100%; height: auto; overflow: hidden; visibility: hidden; } .ggl{ position: relative; width: 85.6%; height: 90px; margin: -5px auto; background: url(img/ggl.png) no-repeat center center; background-size: 100% 100%; } .canvas{ position:absolute; top:2px; left:2.5%; width:95%; height:82px; line-height:82px; text-align:center; z-index: 2;
} .info{ position:absolute; top:2px; left:2.5%; width:95%; height:82px; text-align:center; } .info span{ display: block; font-size: 18px; } #prompt{ line-height: 40px; } .btn{ position: relative; width: 50%; height: 35px; line-height: 35px; background: #df412b; color: #fff; border-radius: 5px; margin: 0 auto; z-index: 1; } .guize{ display: block; width: 85.6%; height: auto; margin: 5% auto 10% auto; border-radius: 5px; } .num{ width: 100%; height: 30px; line-height: 30px; text-align: center; font-size:14px; margin-top: 5%; } #ok, #no{display: none;} .pop{ position: fixed; left: 0; top: 0; z-index: 3; width: 100%; height: 100%; background: rgba(0,0,0,0.6); display: none; } .pop img{ width: 100%; height: auto; overflow: hidden; margin: 15% auto; } </style> </head> <body> <img src="img/banner1.png" class="banner1"/> <div class="ggl" id="top"> <div class="info" id="prize"> <span id="prompt"></span> <span class="btn" id="ok">领取奖品</span> <span class="btn" id="no">再来一次</span> </div> <canvas id="c1" class="canvas"></canvas> </div> <div class="num"> 您还有<span class="num1"></span>次刮卡机会 </div> <!--<img src="img/guize.png" class="guize" />-->
<!-- 遮罩层1抽奖次数已经用完--> <div class="pop pop1"> <img src="img/pop1.png" /> </div> <div class="pop pop2"> <img src="img/pop2.png" id="pop2" /> </div> <script> //控制刮卡次数 var t = 1; //初始化所有数据并且随机产生奖品 var initialize = function () { //剩余刮卡次数 $(‘.num1‘).html(4-t); //随机数 function getRandomNum(lbound, ubound) { return (Math.floor(Math.random() * (ubound - lbound)) + lbound); } var r = getRandomNum(1,100); var btn = document.getElementsByClassName("btn"); for(var i=0; i<btn.length; i++){ btn[i].style.zIndex = ‘1‘; } document.getElementById("no").style.display = "none"; document.getElementById("ok").style.display = "none";
//初始化涂抹面积 isOk = 0;
if(r<t*33){ document.getElementById("prompt").innerHTML="恭喜您，中奖了！" var ok =document.getElementById("ok"); ok.style.display = "block"; //点击领取奖品 ok.onclick = function () {// window.location.href="prize.html" alert("逗你玩，别当真哦~"); }; }else{ document.getElementById("prompt").innerHTML="很遗憾，未中奖！" document.getElementById("no").style.display = "block"; } };
var c1; //画布 var ctx; //画笔 var ismousedown; //标志用户是否按下鼠标或开始触摸 var isOk=0; //标志用户是否已经刮开了一半以上 var fontem = parseInt(window.getComputedStyle(document.documentElement, null)["font-size"]);//这是为了不同分辨率上配合@media自动调节刮的宽度
/* 页面加载后开始初始化画布 */ window.onload = function(){
initialize(); c1 = document.getElementById("c1");
//这里很关键，canvas自带两个属性width、height,我理解为画布的分辨率，跟style中的width、height意义不同。 //最好设置成跟画布在页面中的实际大小一样 //不然canvas中的坐标跟鼠标的坐标无法匹配 c1.width=c1.clientWidth; c1.height=c1.clientHeight; ctx = c1.getContext("2d");
//PC端的处理 c1.addEventListener("mousemove",eventMove,false); c1.addEventListener("mousedown",eventDown,false); c1.addEventListener("mouseup",eventUp,false);
//移动端的处理 c1.addEventListener(‘touchstart‘, eventDown,false); c1.addEventListener(‘touchend‘, eventUp,false); c1.addEventListener(‘touchmove‘, eventMove,false);
//初始化 initCanvas(); }
//初始化画布，画灰色的矩形铺满 function initCanvas(){ //网上的做法是给canvas设置一张背景图片，我这里的做法是直接在canvas下面另外放了个div。 //c1.style.backgroundImage="url(中奖图片.jpg)"; ctx.globalCompositeOperation = "source-over"; ctx.fillStyle = ‘#aaaaaa‘; ctx.fillRect(0,0,c1.clientWidth,c1.clientHeight); ctx.fill();
ctx.font = "Bold 30px Arial"; ctx.textAlign = "center"; ctx.fillStyle = "#999999"; ctx.fillText("刮刮乐",c1.width/2,50);
//把这个属性设为这个就可以做出圆形橡皮擦的效果 //有些老的手机自带浏览器不支持destination-out,下面的代码中有修复的方法 ctx.globalCompositeOperation = ‘destination-out‘; }
//鼠标按下 和 触摸开始 function eventDown(e){ e.preventDefault(); ismousedown=true; }
//鼠标抬起 和 触摸结束 function eventUp(e){ e.preventDefault();
//得到canvas的全部数据 var a = ctx.getImageData(0,0,c1.width,c1.height); console.log(a.data); console.log(a.data.length); var j=0; for(var i=3;i<a.data.length;i+=4){ if(a.data[i]==0)j++; }
//当被刮开的区域等于一半时，则可以开始处理结果 if(j>=a.data.length/8){ isOk = 1; } ismousedown=false; }
//鼠标移动 和 触摸移动 function eventMove(e){ e.preventDefault(); if(ismousedown) { if(e.changedTouches){ e=e.changedTouches[e.changedTouches.length-1]; } var topY = document.getElementById("top").offsetTop; var oX = c1.offsetLeft, oY = c1.offsetTop+topY;
var x = (e.clientX + document.body.scrollLeft || e.pageX) - oX || 0, y = (e.clientY + document.body.scrollTop || e.pageY) - oY || 0;
//画360度的弧线，就是一个圆，因为设置了ctx.globalCompositeOperation = ‘destination-out‘; //画出来是透明的 ctx.beginPath(); ctx.arc(x, y, fontem*1.2, 0, Math.PI * 2,true);
//下面3行代码是为了修复部分手机浏览器不支持destination-out //我也不是很清楚这样做的原理是什么 c1.style.display = ‘none‘; c1.offsetHeight; c1.style.display = ‘inherit‘;
ctx.fill(); }
if(isOk){ var btn = document.getElementsByClassName("btn"); for(var i=0; i<btn.length; i++){ btn[i].style.zIndex = ‘3‘; } document.getElementsByClassName("btn")[0].style.zIndex="3"; } }
//没有中奖再来一次 $("#no").click(function() { if(t>3){ //因该弹出遮罩层提示您的次数已经用完了 $(‘.pop1‘).show(); $(‘.pop1 img‘).click(function(){ $(‘.pop1‘).hide(); }) }else{ t++; //初始化按钮 document.getElementById("no").style.display = "none"; document.getElementById("ok").style.display = "none"; window.onload(); initCanvas();
} });
</script>
</body>
</html>
时间： 2024-10-31 19:47:32