获取手机设备方向

@Override

public void onSensorChanged(SensorEvent event) {

float[] values = event.values;

int orientation = Configuration.ORIENTATION_UNDEFINED;

float X = -values[0];

float Y = -values[1];

float Z = -values[2];

float magnitude = X * X + Y * Y;

// Don't trust the angle if the magnitude is small compared to the y

// value

// 这里是关键，来至于谷歌官方

if (magnitude * 4 >= Z * Z) {

float OneEightyOverPi = 57.29577957855f;

float angle = (float) Math.atan2(-Y, X) * OneEightyOverPi;

orientation = 90 - (int) Math.round(angle);

// normalize to 0 - 359 range

while (orientation >= 360) {

orientation -= 360;

}

while (orientation < 0) {

orientation += 360;

}

}

if(orientation < 45 || orientation >= 315){

screentDirection = 0;

}else if(orientation >= 45 && orientation < 135){

screentDirection = 90;

}else if(orientation >= 135 && orientation < 225){

screentDirection = 180;

}else{

screentDirection = 270;

}

} @Override

	public void onSensorChanged(SensorEvent event) {
		float[] values = event.values;
		int orientation = Configuration.ORIENTATION_UNDEFINED;
		float X = -values[0];
		float Y = -values[1];
		float Z = -values[2];
		float magnitude = X * X + Y * Y;
		// Don't trust the angle if the magnitude is small compared to the y
		// value
		// 这里是关键，来至于谷歌官方
		if (magnitude * 4 >= Z * Z) {
			float OneEightyOverPi = 57.29577957855f;
			float angle = (float) Math.atan2(-Y, X) * OneEightyOverPi;
			orientation = 90 - (int) Math.round(angle);
			// normalize to 0 - 359 range
			while (orientation >= 360) {
				orientation -= 360;
			}
			while (orientation < 0) {
				orientation += 360;
			}
		}
		if(orientation < 45 || orientation >= 315){
			screentDirection = 0;
		}else if(orientation >= 45 && orientation < 135){
			screentDirection = 90;
		}else if(orientation >= 135 && orientation < 225){
			screentDirection = 180;
		}else{
			screentDirection = 270;
		}
	}