在Android M中获取纬度和经度0.0

Question

我遇到的问题是在Android Marshmallow（API 23）中获得价值0.0作为纬度和经度，即6.0。

我已经对此进行了很多搜索，但没有找到它的解决方案。我的代码完全适用于少于23的其他API版本。

我还为selfPermission设置了代码，而且所有代码都正在运行，而不是给我0.0这么晚和很长。

请查看我关注的方式：

GPSTracker.java

public class GPSTracker extends Service implements LocationListener {

    private  Context mContext;

    // Flag for GPS status
    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 = 1000; 

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;

    Activity activity;

    public GPSTracker() {
    }

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

    public Location getLocation() {
        try {


            locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);

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

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

            if (!isGPSEnabled && !isNetworkEnabled) {
                // No network provider is enabled
            } else {
                this.canGetLocation = true;
                if (isNetworkEnabled) {
                    int requestPermissionsCode = 50;
                    if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                        ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, requestPermissionsCode);

                    } else {
                        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 latitude/longitude using GPS Services
                if (isGPSEnabled) {
                    if (location == null) {
                        if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                            ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);

                        } else {
                            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) {
            if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);

            } else {
                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/Wi-Fi enabled
     * @return boolean
     * */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }


    /**
     * Function to show settings alert dialog.
     * On pressing the Settings button it will launch Settings Options.
     * */
    public void showSettingsAlert(){
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing the Settings button.
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });

        // On pressing the cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }


    @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) {
    }


    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }
 }

DashboardActivity.java：

在onCreate（）中我初始化了GPSTracker：

gps = new GPSTracker(mContext,DashboardActivity.this);

        // Check if GPS enabled
        if(gps.canGetLocation()) {

            double latitude = gps.getLatitude();
            double longitude = gps.getLongitude();

            // \n is for new line
            Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
        } else {
            // Can't get location.
            // GPS or network is not enabled.
            // Ask user to enable GPS/network in settings.
            gps.showSettingsAlert();
        }

的AndroidManifest.xml

<permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <permission android:name="android.permission.ACCESS_FINE_LOCATION" />


    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.INTERNET" />

我已经浏览了Stack Overflow中提供的许多链接，但它们都没有帮助我解决这个问题。

我很感激这里有任何帮助。

Answer 1

在 CommonsWare 和 Blackkara 答案的帮助下，我能够解决我的问题。

根据他们的建议，我已经更改了我的代码，并通过调试了解我的代码的每一步。

由于我遇到的问题是我的onLocationChanged（）在Marshmallow的情况下没有被解雇，但令人惊讶的是，在旧设备小于Android M或6.0的情况下它会起火。

为了解决这个问题，我已经更改了我的代码，在这里，我发布了完整的代码，以便任何有相同问题的人都可以摆脱它。

<强> GPSTracker.java

public class GPSTracker extends Service{

    private  Context mContext;

    // Flag for GPS status
    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 = 1000; // 10 meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;

    Activity activity;

    public GPSTracker() {
    }

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

    public Location getLocation() {
        try {


            locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);

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

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

            if (!isGPSEnabled && !isNetworkEnabled) {
                // No network provider is enabled
            } else {
                this.canGetLocation = true;
                if (isNetworkEnabled) {
                    int requestPermissionsCode = 50;

                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, mLocationListener);
                    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 latitude/longitude using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                        ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);

                    } else {
                        locationManager.requestLocationUpdates(
                                LocationManager.GPS_PROVIDER,
                                MIN_TIME_BW_UPDATES,
                                MIN_DISTANCE_CHANGE_FOR_UPDATES, mLocationListener);
                        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() {

    }


    private final LocationListener mLocationListener = new LocationListener() {
        @Override
        public void onLocationChanged(final Location location) {

            if (location != null) {
                latitude = location.getLatitude();
                longitude = location.getLongitude();
            }
        }

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

        }

        @Override
        public void onProviderEnabled(String provider) {

        }

        @Override
        public void onProviderDisabled(String provider) {

        }
    };

    /**
     * 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/Wi-Fi enabled
     * @return boolean
     * */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }


    /**
     * Function to show settings alert dialog.
     * On pressing the Settings button it will launch Settings Options.
     * */
    public void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing the Settings button.
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });

        // On pressing the cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }


    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }
}

<强> DashboardActivity.java

public class DashboardActivity extends Activity {      

    Context mContext;   

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dashboard);

        mContext = this;

        if (ContextCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(DashboardActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);

        } else {
            Toast.makeText(mContext,"You need have granted permission",Toast.LENGTH_SHORT).show();
            gps = new GPSTracker(mContext, DashboardActivity.this);

            // Check if GPS enabled
            if (gps.canGetLocation()) {

                double latitude = gps.getLatitude();
                double longitude = gps.getLongitude();

                // \n is for new line
                Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
            } else {
                // Can't get location.
                // GPS or network is not enabled.
                // Ask user to enable GPS/network in settings.
                gps.showSettingsAlert();
            }
        }           
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        switch (requestCode) {
            case 1: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    // permission was granted, yay! Do the

                    // contacts-related task you need to do.

                    gps = new GPSTracker(mContext, DashboardActivity.this);

                    // Check if GPS enabled
                    if (gps.canGetLocation()) {

                        double latitude = gps.getLatitude();
                        double longitude = gps.getLongitude();

                        // \n is for new line
                        Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
                    } else {
                        // Can't get location.
                        // GPS or network is not enabled.
                        // Ask user to enable GPS/network in settings.
                        gps.showSettingsAlert();
                    }

                } else {

                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.

                    Toast.makeText(mContext, "You need to grant permission", Toast.LENGTH_SHORT).show();
                }
                return;
            }
        }
    }
}

Manifest.xml：

添加的权限

    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.INTERNET" />

在应用程序标记中声明服务：

 <service android:name=".utilities.GPSTracker"/>

Answer 2

首先，删除这些：

<permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<permission android:name="android.permission.ACCESS_FINE_LOCATION" />

这些是由平台定义的，而不是你。

此外，当用户实际授予您权限时，您不会做出反应。请求您的活动中的权限，并且在获得许可之前不要创建GPSTracker的实例。如果checkSelfPermission()表示您已获得许可，那么可能会立即。否则，将使用onRequestPermissionResult()调用活动。

位置工作本身也是错误的，因为您似乎认为您将立即获得一个位置，而在大多数情况下情况并非如此。

Answer 3

你可能有以下原因？

第一个原因

位置提供商没有为您提供0.0值作为纬度和经度。你得到了第一次定义的东西。因为，您没有收到新的位置或getLastKnownLocation（）返回null。因此，纬度和经度变量保持其第一个值（0.0）

double latitude;
double longitude;

第二个原因

每当你调用getLocation（）方法时，getLastKnownLocation（）方法都会做什么，直到onLocationChanged fire！ （取决于提供者）

@Override
public void onLocationChanged(Location location) {

}

详细说明'取决于提供商'

您已请求gps和网络提供商。

requestLocationUpdates(LocationManager.NETWORK_PROVIDER ... mLocationListener);
requestLocationUpdates(LocationManager.GPS_PROVIDER ... mLocationListener);

然后为两个提供者调用了getLastKnownLocation方法

locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

假设这两个提供程序返回null 。在这种情况下，您需要等到onLocationChanged方法被触发。否则，您将从getLastKnownLocation方法获取null，具体取决于提供者

@Override
public void onLocationChanged(final Location location) {

    String providerName =  location.getProvider();

    if(providerName.equals(LocationManager.GPS_PROVIDER)){
        // onLocationChanged method is fired by gps provider.
        // After this point, getLastKnownLocation(); method returns not-null 
        // for LocationManager.GPS_PROVIDER
    }

    if( providerName.equals(LocationManager.NETWORK_PROVIDER)){
        // onLocationChanged method is fired by network provider.
        // After this point, getLastKnownLocation(); method returns not-null 
        // for LocationManager.NETWORK_PROVIDER
    }
}

Answer 4

伙计们，我解决了这个问题，此块中给出的第一个答案很好用。 为了从经度和纬度中删除0.0，只需在手机设置中转到，打开应用程序管理器并授予应用程序权限。它将显示，就像让它等待用户使用一样，我们可以将Dialog授予权限。