Question

我已经按照几个指南来获取我的Android应用程序上的GPS坐标。当我在Android手机上测试它时，它给我0.0纬度和经度。我无法理解为什么会这样，如果有人可以帮助我，我会很高兴。

我现在使用的代码：

这是我的主要活动

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 color: #FF0000;
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/* or if you want to change all h1: */
h1 {
  color: #00FF00 !important;
}
</style>

位置跟踪类

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GPSTracker mGPS = new GPSTracker(this);

TextView text = (TextView) findViewById(R.id.texts);
if(mGPS.canGetLocation ){
mGPS.getLocation();
text.setText("Lat"+mGPS.getLatitude()+"Lon"+mGPS.getLongitude());
}else{
    text.setText("Unabletofind");
    System.out.println("Unable");
   }
}

Android清单

public final class GPSTracker implements LocationListener {

private final Context mContext;

// flag for GPS status
public boolean isGPSEnabled = false;

// flag for network status
boolean isNetworkEnabled = false;

// flag for GPS status
boolean canGetLocation = false;

Location location; // location
double latitude; // latitude
double longitude; // longitude

// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1; // 1 minute

// Declaring a Location Manager
protected LocationManager locationManager;

public GPSTracker(Context context) {
    this.mContext = context;
    getLocation();
}

/**
 * Function to get the user's current location
 * 
 * @return
 */
public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(Context.LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        Log.v("isGPSEnabled", "=" + isGPSEnabled);

        // getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        Log.v("isNetworkEnabled", "=" + isNetworkEnabled);

        if (isGPSEnabled == false && isNetworkEnabled == false) {
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            if (isNetworkEnabled) {
                location=null;
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) {
                location=null;
                if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}

/**
 * Stop using GPS listener Calling this function will stop using GPS in your
 * app
 * */
public void stopUsingGPS() {
    if (locationManager != null) {
        locationManager.removeUpdates(GPSTracker.this);
    }
}

/**
 * Function to get latitude
 * */
public double getLatitude() {
    if (location != null) {
        latitude = location.getLatitude();
    }

    // return latitude
    return latitude;
}

/**
 * Function to get longitude
 * */
public double getLongitude() {
    if (location != null) {
        longitude = location.getLongitude();
    }

    // return longitude
    return longitude;
}

/**
 * Function to check GPS/wifi enabled
 * 
 * @return boolean
 * */
public boolean canGetLocation() {
    return this.canGetLocation;
}

@Override
public void onLocationChanged(Location location) {
}

@Override
public void onProviderDisabled(String provider) {
}

@Override
public void onProviderEnabled(String provider) {
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}

}

我也尝试了其他一些方法，但我手机上的电话一直是0.0，而我似乎无法弄明白为什么。如果有人能帮助我，我将非常感激。感谢

Answer 1

Android GPS有几个很好的在线教程。您还可以参加Udacity的免费在线课程，该课程涵盖谷歌地图和GPS。

您需要实现的不仅仅是位置监听器。您需要实现回调侦听器。在GPS应用程序中，您的类声明看起来应该是这样的。

public class MainActivity extends AppCompatActivity implements
     GoogleApiClient.ConnectionCallbacks,
     GoogleApiClient.OnConnectionFailedListener, LocationListener {
}

现在您需要实现几种新方法。主要是onConnected方法和onConnected方法，您需要添加权限检查。您的onConnected方法应如下所示。

@Override
    public void onConnected(@Nullable Bundle bundle) {
        mLocationRequest = LocationRequest.create();
        mLocationRequest.setInterval(1000);
        mLocationRequest.setFastestInterval(5000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        Location mLastLocation;

        Log.v(LOG_TAG, "Connected");

        int permissionCheck = ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.ACCESS_FINE_LOCATION);
        if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
            Log.v(LOG_TAG, "Permission granted for Location");
        } else {
            Log.v(LOG_TAG, "Permission denied for Location");
        }

        // Here, thisActivity is the current activity
        if (ContextCompat.checkSelfPermission(MainActivity.this,
                android.Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                    android.Manifest.permission.ACCESS_FINE_LOCATION)) {

                // Show an explanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.

            } else {

                // No explanation needed, we can request the permission.

                ActivityCompat.requestPermissions(MainActivity.this,
                        new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
                        LOCATION_REQUEST_CODE);

                // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
                // app-defined int constant. The callback method gets the
                // result of the request.
            }
        }
        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
            mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
            if (mLastLocation != null) {
                latOutPut.setText(Location.convert(mLastLocation.getLatitude(), Location.FORMAT_SECONDS));
                lonOutPut.setText(Location.convert(mLastLocation.getLongitude(), Location.FORMAT_SECONDS));
            }
            LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, MainActivity.this);
        }
    }

在Android手机上测试时GPS坐标为0.0

1 个答案: