基于HTML5实现类似微信手机摇一摇功能(计算摇动次数)

var jsonObject=null;        // 当页面加载完以后会执行window.onload        window.onload = function() {            var times = -1; // 记录摇动次数            var last_time = 0;            var borderSpeed = 800;  // 加速度变化临界值            var x = y = z = last_x = last_y = last_z = 0;            if (window.DeviceMotionEvent) {                window.addEventListener('devicemotion',shake,false);            }            else            {                alert('您的设备不支持摇一摇哦');            }            // 每次手机移动的时候都会执行下面shake函数的代码            function shake(eventData)            {                var acceleration = eventData.accelerationIncludingGravity;                var curTime = new Date().getTime();                var diffTime  = curTime-last_time;                // 每隔100ms进行判断                if (diffTime>100) {                    x = acceleration.x;                    y = acceleration.y;                    z = acceleration.z;                    var speed = Math.abs(x + y + z - last_x - last_y - last_z) / diffTime * 10000;                    // 判断手机确实发生了摇动而不是正常的移动                    if (speed>borderSpeed) {                        times++;                        document.getElementById("text").innerHTML=times+" times";                        // 用户的微信昵称和头像连接发送一次即可，不需要每次都发送                        if (times==0)                        {                            document.forms["insertForm"].headimg.value =img ;                            document.forms["insertForm"].user.value = nickname;                        }                        document.forms["insertForm"].time.value = times;                    }                    last_time = curTime;                    last_x = x;                    last_y = y;                    last_z = z;                }            }        }

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