Android 如何将箭头仅指向特定方向,即向西
我想把我的箭头只指向西方向,不管用户面对的是哪里。下面是我尝试过但没有得到预期结果的代码Android 如何将箭头仅指向特定方向,即向西,android,math,sensors,compass,compass-geolocation,Android,Math,Sensors,Compass,Compass Geolocation,我想把我的箭头只指向西方向,不管用户面对的是哪里。下面是我尝试过但没有得到预期结果的代码 // inside onCreate() sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE); gsensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); msensor = sensorManager.getDefaul
// inside onCreate()
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
gsensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
msensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
packageManager = getPackageManager();
if (packageManager.hasSystemFeature(PackageManager.FEATURE_SENSOR_COMPASS)){
sensorManager.registerListener(this, gsensor, SensorManager.SENSOR_DELAY_GAME);
sensorManager.registerListener(this, msensor, SensorManager.SENSOR_DELAY_GAME);
}else {
Toast.makeText(MainActivity.this,"No Compass Sensor !", Toast.LENGTH_SHORT).show();
}
@Override
public void onSensorChanged(SensorEvent event) {
final float alpha = 0.97f;
synchronized (this){
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER){
mGravity[0] = alpha * mGravity[0] + (1 - alpha)
* event.values[0];
mGravity[1] = alpha * mGravity[1] + (1 - alpha)
* event.values[1];
mGravity[2] = alpha * mGravity[2] + (1 - alpha)
* event.values[2];
}
if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD){
mGeomagnetic[0] = alpha * mGeomagnetic[0] + (1 - alpha)
* event.values[0];
mGeomagnetic[1] = alpha * mGeomagnetic[1] + (1 - alpha)
* event.values[1];
mGeomagnetic[2] = alpha * mGeomagnetic[2] + (1 - alpha)
* event.values[2];
}
float R[] = new float[9];
float I[] = new float[9];
boolean success = SensorManager.getRotationMatrix(R, I, mGravity, mGeomagnetic);
if (success){
float orientation[] = new float[3];
SensorManager.getOrientation(R, orientation);
azimuth = (float) Math.toDegrees(orientation[0]);
Log.i("DegreeA",""+azimuth);
azimuth = (azimuth + 360) % 270;
Log.i("DegreeA",""+azimuth);
adjustThearrow();
}
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
private void adjustThearrow(){
Matrix matrix = new Matrix();
imageview.setScaleType(ImageView.ScaleType.MATRIX);
matrix.postRotate((float) -azimuth, imageview.getDrawable().getBounds().width()/2,
imageview.getDrawable().getBounds().height()/2);
imageview.setImageMatrix(matrix);
}
在下面的代码行中,如果我设置360而不是270,它会给我一个只指向北方的箭头,并且它会平滑地旋转
azimuth = (azimuth + 360) % 360;
但如果我想让我的代码只面向西方向的箭头,我将代码设置为:
azimuth = (azimuth + 360) % 270;
但这一次旋转并不平滑
请帮助我如何进行。如果提供任何替代解决方案会更好。您替换了错误的号码:方位=(方位+270)%360;谢谢你的帮助,我会尝试一下,让你知道。