利用Javascript实现简单的转盘抽奖
(编辑：jimmy 日期: 2024/11/17 浏览：3 次 )
首先来看看接口说明：
var _rotate = new iRotate('#div',{
start : 0, //开始角度，可不写，默认0
end :45, //结束角度
time :5000, //持续时间，可不写，默认1000
easing : 'easeOut', //动画形式，目前只有'linear'和'easeOut'两种，可不写，默认'easeOut'
callback : function(){ //回调函数
//this为当前对象
}
});
_rotate.stop(function(){ //停止回调函数
//this为当前对象
});
实现的效果图如下：
完整的示例代码如下：
<!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=utf-8" />
<title>简单转盘效果</title>
<style>
#RotateDiv{border-radius:50px 0 50px 50px }
#RotateDiv,#RotateDiv2{ width: 50px;height: 50px; color: #fff;text-align: center; line-height: 50px; background: #444; position: relative; margin: 20px;border-radius:50px 0 50px 50px}
</style>
</head>
<body>
<p>举例子：</p>
<p> <button id="RotateBtn">开始抽奖</button> </p>
<div id="RotateDiv"></div>
<p>默认转动：</p>
<p> <button id="RotateBtn2">开始抽奖2</button> </p>
<div id="RotateDiv2"></div>
<script type="text/javascript">
window.iRotate = (function(w,d){
function R(obj,json){
this.obj = (typeof obj=='object') ? obj : d.querySelector(obj);
this.startTime = Date.now();
this.timer = null;
this.rotate(json);
};
R.prototype = {
rotate : function(json){
var t = this,times = json['time'] || 1000;
clearInterval(t.timer)
t.timer = setInterval(function(){
var changeTime = Date.now(),
tm = times - Math.max(0,t.startTime - changeTime + times),
value = Tween[json['easing'] || 'easeOut'](tm,+json['start'] || 0,json['end'] - (+json['start'] || 0),times);
t.obj.style['transform'] = t.obj.style['-webkit-transform'] = 'rotate('+value%360+'deg)';
t.obj.setAttribute('data-rotate',value%360)
if(tm==times){
clearInterval(t.timer);
json.callback && json.callback.call(t.obj)
}
},10)
},
stop : function(fn){
clearInterval(this.timer);
fn && fn.call(this.obj)
}
};
return R;
})(window,document);
var Tween = {linear: function (t, b, c, d){return c*t/d + b;},easeOut: function(t, b, c, d){return -c *(t/=d)*(t-2) + b;}}
//默认转动
;(function(){
var off = true,off2 = true;
RotateBtn.onclick = function(){
if(!off) return //判断是否在旋转
off = false
new iRotate('#RotateDiv',{
end :45+1800,
time :5000,
callback : function(){ //回调函数
this.innerHTML = this.getAttribute('data-rotate')
off = true
}
});
}
var r = null;
function rotate2(){ //递归持续旋转
r = new iRotate('#RotateDiv2',{
start : 0,
end :360,
time :1000,
easing : 'linear',
callback : function(){
rotate2()
}
});
}
rotate2()
RotateBtn2.onclick = function(){
if(!off2) return //判断是否在旋转
off2 = false
r.stop(); //停止之前的旋转
new iRotate('#RotateDiv2',{
start : RotateDiv2.getAttribute('data-rotate'),
end :65+1800,
time :5000,
callback : function(){ //回调函数
this.innerHTML = this.getAttribute('data-rotate')
off2 = true
}
});
}
})();
</script>
</body>
</html>
总结
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