private boolean isGpsEnabled()
{
    LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
    return service.isProviderEnabled(LocationManager.GPS_PROVIDER)&&service.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
}

在我看来，这个if子句很容易检查位置服务是否可用:

LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
if(!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) && !locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
        //All location services are disabled

}

您可以使用下面的代码来检查是否启用gps提供程序和网络提供程序。

LocationManager lm = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
boolean gps_enabled = false;
boolean network_enabled = false;

try {
    gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
} catch(Exception ex) {}

try {
    network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
} catch(Exception ex) {}

if(!gps_enabled && !network_enabled) {
    // notify user
    new AlertDialog.Builder(context)
        .setMessage(R.string.gps_network_not_enabled)
        .setPositiveButton(R.string.open_location_settings, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface paramDialogInterface, int paramInt) {
                context.startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
            }
        })
        .setNegativeButton(R.string.Cancel,null)
        .show();    
}

在清单文件中，您需要添加以下权限

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

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();
    }

    LocationManager lm = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
    boolean gps_enabled = false;
    boolean network_enabled = false;

    try {
        gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
    } catch(Exception e){
         e.printStackTrace();
    }

    try {
        network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
    } catch(Exception e){
         e.printStackTrace();
    }

    if(!gps_enabled && !network_enabled) {
        // notify user
        new AlertDialog.Builder(this)
                .setMessage("Please turn on Location to continue")
                .setPositiveButton("Open Location Settings", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface paramDialogInterface, int paramInt) {
                        startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                    }

                }).
                setNegativeButton("Cancel",null)
                .show();
    }

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;
    }
}