如何通过html5实现摇一摇的功能

来源：凌优教育

原理：使用DeviceMotion实现，关于DeviceMotion介绍可以查看
https://developer.mozilla.org/en-US/docs/Web/Reference/Events/devicemotion

通过DeviceMotionEvent，可以获得accelerationIncludingGravity的x,y,z属性，根据x,y,z属性的变化来判断设备是否有摇一摇的事件发生。

accelerationIncludeingGravity说明：
The acceleration of the device. This value includes the effect of gravity, and may be the only value available on devices that don’t have a gyroscope to allow them to properly remove gravity from the data.

代码如下：

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html>
 <head>
 <meta http-equiv="content-type" content="text/html;charset=utf-8"> 
 <title> html5使用DeviceMotionEvent实现摇一摇 </title>
 <style type="text/css">
 .center{position:absolute; width:0px; height:480px; left:50%; top:50%; margin-left:-320px; margin-top:-240px; line-height:480px; text-align:center; font-size:100px; }
 .normal{background:#000000;}
 .normal .txt{color:#FFFFFF;}
 .doing{background:#FF0000;}
 .doing .txt{color:#FFFF00;}
 </style>
 </head>
 <body id="mybody" class="normal">
 <p id="txt" class="txt center">请执行摇一摇</p>
 </body>
 <script type="text/javascript">
 var doing = 0; // 判断是否在动画显示中
 var speed = 23; // 定义摇动的速度数值
 var lastx = 0; var lasty = 0; var lastz = 0; function handleMotionEvent(event) {
 var x = event.accelerationIncludingGravity.x; var y = event.accelerationIncludingGravity.y; var z = event.accelerationIncludingGravity.z; if(doing==0){ if(Math.abs(x-lastx)>speed || Math.abs(y-lasty)>speed){
 doing = 1;
 show();
 }
 }
 lastx = x;
 lasty = y;
 lastz = z;
 } function show(){
 document.getElementById('mybody').className = 'doing';
 document.getElementById('txt').innerHTML = '执行了摇一摇';
 setTimeout(function(){
 doing=0; 
 document.getElementById('mybody').className='normal';
 document.getElementById('txt').innerHTML = '请执行摇一摇';
 },3000);
 }
 window.addEventListener("devicemotion", handleMotionEvent, true); </script></html>

本文介绍了通过html5实现摇一摇的功能，更多相关内容请关注Gxl网。