android 通过加速度传感器实现手机来电时翻转静音

来源：互联网发布：海贼王887 知乎编辑：程序博客网时间：2024/06/08 06:06

实现思路

通过加速度传感器获取 X，Y，Z 三轴所受的重力
计算在指定的时间段内，手机在 X，Y，Z 矢量和的方向上的速度
如果速度大于指定的速度阀值，判定手机当前在剧烈抖动；并结束当前方法
通过Z轴的改变判断手机是否发生反转，如果是调用AudioManager的setRingerMode(AudioManager.RINGER_MODE_SILENT)方法使手机静音

代码

public class MainActivity extends AppCompatActivity {    SensorManager mSensorManager = null;    AccelerometerSilentListener mAccelerometerSilentListener = null;    AudioManager mAudioManager = null;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);        Sensor sensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);        mAccelerometerSilentListener = new AccelerometerSilentListener();        mSensorManager.registerListener(mAccelerometerSilentListener, sensor, SensorManager.SENSOR_DELAY_NORMAL);    }    @Override    protected void onDestroy() {        super.onDestroy();        if (mSensorManager != null) {            mSensorManager.unregisterListener(mAccelerometerSilentListener);        }    }    private class AccelerometerSilentListener implements SensorEventListener {        private static final int SPEED_LIMIT = 800; //速度阀指        private static final int UPDATE_INTERNAL_TIME = 60; //两次取样时间差        private long lastTime = 0;        private float lastX = 0;        private float lastY = 0;        private float lastZ = 0;        private boolean isUp = false;        @Override        public void onSensorChanged(SensorEvent event) {            long currentTime = System.currentTimeMillis();            float internalTime = currentTime - lastTime;            if (internalTime < UPDATE_INTERNAL_TIME) {                return;            }            lastTime = currentTime;            float x = event.values[0];            float y = event.values[1];            float z = event.values[2];            float deltaX = x - lastX;            float deltaY = y - lastY;            float deltaZ = z - lastZ;            lastX = x;            lastY = y;            lastZ = z;            double speed = Math.sqrt(deltaX*deltaX + deltaY*deltaY + deltaZ*deltaZ) / internalTime * 10000; //算出后速度为 mm/s            if (speed > SPEED_LIMIT) {                return;            }            if (x > -1 && x < 1 && y > -1 && y < 1) {                if (z > 0) {                    isUp = true;                } else {                    isUp = false;                }            } else {                if (z > -10f && z < -9.6f && isUp) {                    mAudioManager.setRingerMode(AudioManager.RINGER_MODE_SILENT);                } else if (z > 9.6f && z < 10f && !isUp) {                    mAudioManager.setRingerMode(AudioManager.RINGER_MODE_SILENT);                }            }        }        @Override        public void onAccuracyChanged(Sensor sensor, int accuracy) {        }    }}

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