我想构建一个Android应用程序，用于计算自行车行驶的距离，并根据所覆盖的总距离发送维护或服务通知。有人请帮助我！
public class Main2Activity extends AppCompatActivity implements View.OnClickListener {
Button start, stop;
TextView distanceValue, dist, last;
DistanceService gps;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
start = (Button) findViewById(R.id.btn_start);
//stop = (Button) findViewById(R.id.btn_stop);
distanceValue = (TextView) findViewById(R.id.distance);
start.setOnClickListener(this);
// stop.setOnClickListener(this);
// dist = (TextView) findViewById(R.id.txt_dist);
//last = (TextView) findViewById(R.id.txt_last);
}
@Override
public void onRequestPermissionsResult(int requestCode,@NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode) {
case Utility.REQUEST_CODE_ASK_PERMISSIONS:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getApplicationContext(), "Granted", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_LONG).show();
}
break;
}
}
@Override
public void onClick(View v) {
int id = v.getId();
switch (id) {
case R.id.btn_start:
gps = new DistanceService(Main2Activity.this,distanceValue);
startService(new Intent(this, DistanceService.class));
break;
}
}
}
Distance Service.java
.............
public class DistanceService {
private static final int REQUEST_CODE_ASK_PERMISSIONS = 123;
double distanceKm,distanceMeters;
protected LocationManager locManager;
private LocationListener locListener = new myLocationListener();
static final Double EARTH_RADIUS = 6371.00;
private boolean gps_enabled = false;
private boolean network_enabled = false;
private final Context context;
TextView tv;
public DistanceService(Context ctx,TextView textView){
context=ctx;
tv=textView;
location();
}
public void location() {
locManager = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
try {
gps_enabled = locManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
} catch (Exception ex) {
ex.printStackTrace();
Toast.makeText(context,ex.toString(),Toast.LENGTH_LONG).show();
}
try {
network_enabled = locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
} catch (Exception ex) {
}
Log.v("Debug", "in on create.. 2");
if (gps_enabled) {
checkPermission(context);
locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locListener);
Log.v("Debug", "Enabled..");
}
if (network_enabled) {
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,0,0,locListener);
Log.v("Debug", "Disabled..");
}
Log.v("Debug", "in on create..3");
}
private class myLocationListener implements LocationListener
{
double lat_old=0.0;
double lon_old=0.0;
double lat_new;
double lon_new;
double time=10;
double speed=0.0;
@Override
public void onLocationChanged(Location location) {
Log.v("Debug", "in onLocation changed..");
if(location!=null){
checkPermission(context);
locManager.removeUpdates(locListener);
//String Speed = "Device Speed: " +location.getSpeed();
lat_new=location.getLongitude();
lon_new =location.getLatitude();
String longitude = "Longitude: " +location.getLongitude();
String latitude = "Latitude: " +location.getLatitude();
double distance =getDistance(lat_new, lon_new, lat_old, lon_old);
speed = distance/time;
tv.setText( longitude+"\n"+latitude+"\nDistance is: "
+distance+"\nSpeed is: "+speed);
Toast.makeText(context, longitude+"\n"+latitude+"\nDistance is: "
+distance+"\nSpeed is: "+speed , Toast.LENGTH_SHORT).show();
// tv.setText(longitude+"\n"+latitude+"\nDistance is: "
// +distance+"\nSpeed is: "+speed );
lat_old=lat_new;
lon_old=lon_new;
}
}
@Override
public void onProviderDisabled(String provider) {}
@Override
public void onProviderEnabled(String provider) {}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
}
public double getDistance(double lat1, double lon1, double lat2, double lon2){
Location locationA = new Location("point A");
locationA.setLatitude(lat1);
locationA.setLongitude(lon1);
Location locationB = new Location("point B");
locationB.setLatitude(lat2);
locationB.setLongitude(lon2);
distanceMeters = locationA.distanceTo(locationA);
distanceKm = distanceMeters / 1000f;
return distanceKm;
// last.setText("mtr:"+distanceMeters+"km:"+String.format("%.2f Km",distanceKm ));
}
// public double CalculationByDistance(double lat1, double lon1, double lat2, double lon2) {
// double Radius = EARTH_RADIUS;
// double dLat = Math.toRadians(lat2-lat1);
// double dLon = Math.toRadians(lon2-lon1);
// double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
// Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
// Math.sin(dLon/2) * Math.sin(dLon/2);
// double c = 2 * Math.asin(Math.sqrt(a));
// return Radius * c;
// }
public static boolean checkPermission(final Context context)
{
int currentAPIVersion = Build.VERSION.SDK_INT;
if(currentAPIVersion>= 23)
{
if (ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
ContextCompat.checkSelfPermission (context, Manifest.permission.ACCESS_COARSE_LOCATION )!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.ACCESS_FINE_LOCATION)||
ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.ACCESS_COARSE_LOCATION) ) {
AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
alertBuilder.setCancelable(true);
alertBuilder.setTitle("Permission necessary");
alertBuilder.setMessage("External storage permission is necessary");
alertBuilder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions((Activity) context,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, REQUEST_CODE_ASK_PERMISSIONS );
}
});
AlertDialog alert = alertBuilder.create();
alert.show();
} else {
ActivityCompat.requestPermissions((Activity) context,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, REQUEST_CODE_ASK_PERMISSIONS );
}
return false;
} else {
return true;
}
} else {
return true;
}
}
答案 0 :(得分：0)
为了计算得到旧的Lat-Lang并获得新的Lat-Lang并找到它们之间的距离
logistic_regression()