Java Android-等待更改纬度和经度
情况: 我有一个OpenActivity,我想在其中有一个当前的位置,要做到这一点,我要求所有需要的权限,之后,我想打开新的活动,并向它提供这些数据 问题:在第一次发射时,我提供纬度和经度=0.00 问题:我如何解决这个问题?我只想在我的位置设置正确时调用新活动 这是我的代码:Java Android-等待更改纬度和经度,java,android,google-maps,Java,Android,Google Maps,情况: 我有一个OpenActivity,我想在其中有一个当前的位置,要做到这一点,我要求所有需要的权限,之后,我想打开新的活动,并向它提供这些数据 问题:在第一次发射时,我提供纬度和经度=0.00 问题:我如何解决这个问题?我只想在我的位置设置正确时调用新活动 这是我的代码: public class OpenActivity extends AppCompatActivity { public static final int PERMISSIONS_REQUEST_LOCATION
public class OpenActivity extends AppCompatActivity {
public static final int PERMISSIONS_REQUEST_LOCATION = 99;
public static final int PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 98;
public Boolean networkPermission=false;
public Boolean locationPermission=false;
public Boolean storagePermission=false;
private TrackGPS gps = null;
double longitude=0.00;
double latitude=0.00;
private Location location=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_open);
checkLocationPermission();
checkStoragePermission();
networkPermission=checkNetworkState();
getLocation();
Intent i = new Intent(OpenActivity.this,MainActivity.class);
i.putExtra("location",location);
startActivity(i);
}
public void getLocation(){
if(locationPermission){
gps = new TrackGPS(OpenActivity.this);
if(gps.canGetLocation() && gps.getLoc()!=null){
location=gps.getLoc();
latitude=location.getLatitude();
longitude=location.getLongitude();
}
else
{
if (!gps.canGetLocation())
{
gps.showSettingsAlert();
}
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode) {
case PERMISSIONS_REQUEST_LOCATION:
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
locationPermission=true;
} else {
locationPermission=false;
}
break;
case PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
{
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
storagePermission=true;
} else {
storagePermission=false;
}
}
break;
}
}
private void checkStoragePermission() {
if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_EXTERNAL_STORAGE)) {
new AlertDialog.Builder(this)
.setTitle("Storage Permission Needed")
.setMessage("This app needs the Storage permission, please accept to use Storage functionality")
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
ActivityCompat.requestPermissions(OpenActivity.this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE );
}
})
.create()
.show();
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE );
}
}else{
storagePermission=true;
}
}
private void checkLocationPermission() {
if (ContextCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
android.Manifest.permission.ACCESS_FINE_LOCATION)) {
new AlertDialog.Builder(this)
.setTitle("Location Permission Needed")
.setMessage("This app needs the Location permission, please accept to use location functionality")
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
ActivityCompat.requestPermissions(OpenActivity.this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
PERMISSIONS_REQUEST_LOCATION );
}
})
.create()
.show();
} else {
ActivityCompat.requestPermissions(this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
PERMISSIONS_REQUEST_LOCATION );
}
}else{
locationPermission=true;
}
}
protected boolean checkNetworkState(){
ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(OpenActivity.this.CONNECTIVITY_SERVICE);
if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED ||
connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) {
return true ;
}
else {
return false;
}
}
}
TrackGPS.java
public class TrackGPS extends Service implements LocationListener {
private final Context mContext;
boolean checkGPS = false;
boolean checkNetwork = false;
boolean canGetLocation = false;
Location loc;
double latitude;
double longitude;
public Location getLoc() {
return loc;
}
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
protected LocationManager locationManager;
public TrackGPS(Context mContext) {
this.mContext = mContext;
getLocation();
}
private Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
checkGPS = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
checkNetwork = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!checkGPS && !checkNetwork) {
Toast.makeText(mContext, "No access", Toast.LENGTH_SHORT).show();
} else {
this.canGetLocation = true;
if (checkNetwork) {
try {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null) {
loc = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
if (loc != null) {
latitude = loc.getLatitude();
longitude = loc.getLongitude();
}
}
catch(SecurityException e){
}
}
}
if (checkGPS) {
if (loc == null) {
try {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null) {
loc = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (loc != null) {
latitude = loc.getLatitude();
longitude = loc.getLongitude();
}
}
} catch (SecurityException e) {
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return loc;
}
public double getLongitude() {
if (loc != null) {
longitude = loc.getLongitude();
}
return longitude;
}
public double getLatitude() {
if (loc != null) {
latitude = loc.getLatitude();
}
return latitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
alertDialog.setTitle("GPS non attivo");
alertDialog.setMessage("E' necessario abilitare il GPS, vuoi abilitarlo");
alertDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
((Activity)mContext).finish();
}
});
alertDialog.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show();
}
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(TrackGPS.this);
}
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
}
在gradle:编译'com.google.android.gms:play services:9.4.0'
用“onlyoctaionchanged”方法调用您的意图。在“OnLocationChanged”方法中定义一个条件,以检查您是否获得了正确的位置。如果此条件为真,则传递意图,否则不执行任何操作。
“OnLocationChanged”方法不断地调用,直到您停止为止。
希望这会有所帮助。我自己解决了这个问题,我已经实现了一个回调方法,我现在不知道它是否有效,但是否有效,我发布了我添加/更新的新行代码: TrackGPS.java
public interface Icall{
void call(Location location);
}
private Icall callerActivity;
public void show(Location posizione){
callerActivity.call(posizione);
}
@Override
public void onLocationChanged(Location location) {
this.show(location);
}
我更新了构造函数:
public TrackGPS(Context mContext,Activity activity) {
this.mContext = mContext;
callerActivity=(Iprova)activity;
getLocation();
}
在OpenActivity.class中,我实现了Icall:
public class OpenActivity extends AppCompatActivity implements TrackGPS.ICall
更改了对TrackGPS对象的调用:
gps = new TrackGPS(OpenActivity.this, (Activity)this);
和覆盖方法:
@Override
public void call(Location location) {
//code to call
}
我希望这能为某人服务。开始吧。然后,在获得许可之前,不要调用
getLocation()
。然后,在从LocationListener
获取位置之前,不要调用startActivity()
(因为getLastKnownLocation()
可能会返回null
)。@commonware我如何“在获得许可之前不要调用getLocation()”?如果我使用正常条件,不工作,如果我使用循环条件,我的程序在循环中崩溃。这种方法似乎解决了部分问题,因为在这种情况下,当我的位置改变时,我确实可以获得新的活动,但我将控制引用到我的TrackGPS类而不是OpenActivity.class也是正确的