我在设置 GPS 服务时遇到问题。我想检查 GPS 是否启用。如果它被禁用，它将显示一个对话框让用户打开它。问题是它不等待用户启用 GPS 并获取位置。
我有一堂课
public class GPSTracker extends Service implements LocationListener{
private final Context mContext;
boolean isGPSEnable = false;
boolean isNetworkEnable = false;
boolean canGetLocation = false;
Location location;
double latitude;
double longitude;
private static final long MIN_DISTANCE_FOR_UPDATE = 10; // 10 meters
private static final long MIN_TIME_BW_UPDATE = 1000 * 60 * 1; // 1 minute
protected LocationManager locationManager;
public GPSTracker(Context ctx) {
this.mContext = ctx;
getLocation();
}
public Location getLocation()
{
try {
locationManager = (LocationManager)mContext.getSystemService(LOCATION_SERVICE);
isGPSEnable = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnable = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if(!isGPSEnable)
{
showSettingsGPSAlert();
}
else if(!isNetworkEnable)
{
showSettingsNetWorkAlert();
}
else
{
this.canGetLocation = true;
if(isNetworkEnable)
{
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATE,
MIN_DISTANCE_FOR_UPDATE, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
if (isGPSEnable) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATE,
MIN_DISTANCE_FOR_UPDATE, 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 ex)
{
Log.e("<<Location Error>>",ex.getMessage());
}
return location;
}
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
public boolean canGetGPS() {
return this.isGPSEnable;
}
public boolean canGetNetwork() {
return this.isNetworkEnable;
}
public void showSettingsGPSAlert(){
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 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.startService(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
public void showSettingsNetWorkAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("NetWork is settings");
// Setting Dialog Message
alertDialog.setMessage("NetWork is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_NETWORK_OPERATOR_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing 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 intent) {
return null;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
我有课可以使用它
public class RestaurantListFragment extends ListFragment {
private ArrayList<Restaurant> restaurants;
private SQLDataHelper dataHelper;
private GPSTracker gps;
private double UserLatitude;
private double UserLongitude;
private ProgressDialog progressBar;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.restaurant_list, null);
}
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
gps = new GPSTracker(getActivity());
UserLatitude = gps.getLatitude();
UserLongitude = gps.getLongitude();
Toast.makeText(getActivity(),UserLatitude + "|" + UserLongitude,Toast.LENGTH_SHORT).show();
dataHelper = new SQLDataHelper(getActivity(), "restaurantDB");
restaurants = new ArrayList<Restaurant>();
dataHelper.openDB();
Cursor cursor = dataHelper.query("Restaurant", new String[]{"Id", "ResName", "Logo", "Address", "Latitude", "Longitude"}, null
, null, null, null, null);
if (cursor.moveToFirst()) {
do {
Restaurant restaurant = new Restaurant();
restaurant.setId(cursor.getInt(0));
restaurant.setResName(cursor.getString(1));
restaurant.setLogo(cursor.getString(2));
restaurant.setAddress(cursor.getString(3));
restaurants.add(restaurant);
} while (cursor.moveToNext());
}
//Collections.sort(restaurants);
RestaurantAdapter restaurantAdapter = new RestaurantAdapter(getActivity(),restaurants);
setListAdapter(restaurantAdapter);
}
}
启用 GPS 时它工作正常。我希望用户可以先打开它。之后它显示用户位置。然后它可以查询数据库和 setListAdapter 。感谢您的任何建议。