我使用第一个代码开始创建方法isLocationEnabled

 private LocationManager locationManager ;

protected boolean isLocationEnabled(){
        String le = Context.LOCATION_SERVICE;
        locationManager = (LocationManager) getSystemService(le);
        if(!locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)){
            return false;
        } else {
            return true;
        }
    }

和我检查条件，如果true打开地图和false给意图ACTION_LOCATION_SOURCE_SETTINGS

    if (isLocationEnabled()) {
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        locationClient = getFusedLocationProviderClient(this);
        locationClient.getLastLocation()
                .addOnSuccessListener(new OnSuccessListener<Location>() {
                    @Override
                    public void onSuccess(Location location) {
                        // GPS location can be null if GPS is switched off
                        if (location != null) {
                            onLocationChanged(location);

                            Log.e("location", String.valueOf(location.getLongitude()));
                        }
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        Log.e("MapDemoActivity", e.toString());
                        e.printStackTrace();
                    }
                });


        startLocationUpdates();

    }
    else {
        new AlertDialog.Builder(this)
                .setTitle("Please activate location")
                .setMessage("Click ok to goto settings else exit.")
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                        startActivity(intent);
                    }
                })
                .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        System.exit(0);
                    }
                })
                .show();
    }

到2020年

最近，最好和最短的方法是

@SuppressWarnings("deprecation")
public static Boolean isLocationEnabled(Context context) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
        // This is a new method provided in API 28
        LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
        return lm.isLocationEnabled();
    } else {
        // This was deprecated in API 28
        int mode = Settings.Secure.getInt(context.getContentResolver(), Settings.Secure.LOCATION_MODE,
                Settings.Secure.LOCATION_MODE_OFF);
        return (mode != Settings.Secure.LOCATION_MODE_OFF);
    }
}

您可以使用此代码引导用户到设置，在那里他们可以启用GPS:

    locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    if( !locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) ) {
        new AlertDialog.Builder(context)
            .setTitle(R.string.gps_not_found_title)  // GPS not found
            .setMessage(R.string.gps_not_found_message) // Want to enable?
            .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialogInterface, int i) {
                    owner.startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                }
            })
            .setNegativeButton(R.string.no, null)
            .show();
    }

这是一个非常有用的方法，如果启用了Location服务，它将返回“true”:

public static boolean locationServicesEnabled(Context context) {
        LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
        boolean gps_enabled = false;
        boolean net_enabled = false;

        try {
            gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
        } catch (Exception ex) {
            Log.e(TAG,"Exception gps_enabled");
        }

        try {
            net_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
        } catch (Exception ex) {
            Log.e(TAG,"Exception network_enabled");
        }
        return gps_enabled || net_enabled;
}

我使用这样的方式NETWORK_PROVIDER，但你可以添加和GPS。

LocationManager locationManager;

在onCreate中

   isLocationEnabled();
   if(!isLocationEnabled()) {
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle(R.string.network_not_enabled)
                .setMessage(R.string.open_location_settings)
                .setPositiveButton(R.string.yes,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                            }
                        })
                .setNegativeButton(R.string.cancel,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                dialog.cancel();
                            }
                        });
        AlertDialog alert = builder.create();
        alert.show();
    } 

检查方法

protected boolean isLocationEnabled(){
    String le = Context.LOCATION_SERVICE;
    locationManager = (LocationManager) getSystemService(le);
    if(!locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)){
        return false;
    } else {
        return true;
    }
}

能用最简单的方法做吗

private boolean isLocationEnabled(Context context){
int mode =Settings.Secure.getInt(context.getContentResolver(), Settings.Secure.LOCATION_MODE,
                        Settings.Secure.LOCATION_MODE_OFF);
                final boolean enabled = (mode != android.provider.Settings.Secure.LOCATION_MODE_OFF);
return enabled;
}