我想实现三件事：
1）基于位置传感器实现指南针+获取当前坐标
2) 将方位设置到固定的目的地
3）一旦轴承设置好，我想设置一个红色的罗盘指针，无论手机旋转如何，它都会继续指向那个固定的轴承。
到目前为止，我已经完成了 1 + 2。关于 3 - 我设法将针指向正确的方向，但是随着手机旋转 - 针也旋转，失去了正确的方向。我已经尝试了很多事情，但我无法让它发挥作用。
还有一个问题：如果bearingTo() 方法计算两个位置之间的度数——它是否考虑了地球曲率？如果没有，这只对近距离是准确的......希望它是:-)
我将不胜感激任何帮助。
这是我的代码 - 检查注释以获取解释。提前致谢！
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
tvCurrAzim = (TextView) findViewById(R.id.tvaz);
tvCurrLat = (TextView) findViewById(R.id.tvlat);
tvCurrLng = (TextView) findViewById(R.id.tvlng);
tvBearing = (TextView) findViewById(R.id.tvbearing);
tvIndicator = (TextView) findViewById(R.id.tvindicator);
ivCompass = (ImageView) findViewById(R.id.imageView1); //compass ImageView
ivArrow = (ImageView) findViewById(R.id.imageView2); //Red Needle ImageView
// Get the location manager
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, true);
location = locationManager.getLastKnownLocation(provider);
tvCurrLat.setText(String.valueOf(location.getLatitude()));
tvCurrLng.setText(String.valueOf(location.getLongitude()));
from = new Location(location); //creating new Location object
to = new Location(location); //creating new Location object
//setting lat,lng to destination Location
to.setLatitude(newLat);
to.setLongitude(newLng);
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
mCompass = mSensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
}
// Compass Sensor Methods:
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
public void onSensorChanged(SensorEvent event) {
// setting animation for compass
azimuth = Math.round(event.values[0]);
tvCurrAzim.setText(Float.toString(azimuth));
// get the angle around the z-axis rotated
// float degree = Math.round(event.values[0]);
// create a rotation animation (reverse turn degree degrees)
RotateAnimation ra = new RotateAnimation(currentDegree, -azimuth,
Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
0.5f);
// how long the animation will take place
ra.setDuration(210);
// set the animation after the end of the reservation status
ra.setFillAfter(true);
// Start the animation
ivCompass.startAnimation(ra);
currentDegree = -azimuth;
pointArrow();
}
// Location Manager Methods:
public void setBearing() {
from.setLatitude(location.getLatitude()); //setting lat,lng to origin Location
from.setLongitude(location.getLongitude());
bearing = Math.round(from.bearingTo(to));
tvBearing.setText(String.valueOf(bearing));
hasBearing = true;
ivArrow.setVisibility(View.VISIBLE);
}
public void pointArrow() {
if (hasBearing) { //once bearing is set
// get the angle around the z-axis rotated
float degree1 = Math.round(azimuth) - (float) bearing;
// create a rotation animation (reverse turn degree degrees)
RotateAnimation ra1 = new RotateAnimation(currentDegree1, -degree1,
Animation.RELATIVE_TO_SELF, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f);
// how long the animation will take place
ra1.setDuration(210);
// set the animation after the end of the reservation status
ra1.setFillAfter(true);
// Start the animation
ivArrow.startAnimation(ra1);
currentDegree1 = -degree1;
//THIS METHOD WORKS TO POINT THE NEEDLE IN CORRECT DIRECTION, BUT AS PHONE ROTATES THE NEEDLE ROTATES TOO.
//I WANT IT TO KEEP POINTING IN FIXED DIRECTION REGARDLESS OF PHONE ROTATION
}
}
@Override
public void onLocationChanged(Location location) {
tvCurrLat.setText(String.valueOf(location.getLatitude()));
tvCurrLng.setText(String.valueOf(location.getLongitude()));
setBearing();
locationManager.removeUpdates(this);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
protected void onPause() {
// Unregister the listener
super.onPause();
locationManager.removeUpdates(this);
mSensorManager.unregisterListener(this);
ivArrow.setVisibility(View.INVISIBLE);
}
@Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 1000, 1, this);
mSensorManager.registerListener(this, mCompass,
SensorManager.SENSOR_DELAY_GAME);
}