微信小程序视频横屏-监听设备方向

// 0为竖屏，1为横屏
let lastState = 0;
let lastTime = Date.now();

wx.startAccelerometer();

wx.onAccelerometerChange((res) => {
const now = Date.now();

// 500ms检测一次
if (now - lastTime < 500) {
return;
}
lastTime = now;

let nowState;

// 57.3 = 180 / Math.PI
const Roll = Math.atan2(-res.x, Math.sqrt(res.y * res.y + res.z * res.z)) * 57.3;
const Pitch = Math.atan2(res.y, res.z) * 57.3;

// console.log(Roll:  + Roll, Pitch:  + Pitch)

// 横屏状态
if (Roll > 50) {
if ((Pitch > -180 && Pitch < -60) || (Pitch > 130)) {
nowState = 1;
} else {
nowState = lastState;
}

} else if ((Roll > 0 && Roll < 30) || (Roll < 0 && Roll > -30)) {
let absPitch = Math.abs(Pitch);

// 如果手机平躺，保持原状态不变，40容错率
if ((absPitch > 140 || absPitch < 40)) {
nowState = lastState;
} else if (Pitch < 0) { /*收集竖向正立的情况*/
nowState = 0;
} else {
nowState = lastState;
}
}
else {
nowState = lastState;
}

// 状态变化时，触发
if (nowState !== lastState) {
lastState = nowState;
if (nowState === 1) {
console.log(change:横屏);
} else {
console.log(change:竖屏);
}
}
});