getLastKnownLocation 在更高版本的 Android(6 及更高版本)中不起作用

Question

我正在尝试创建一个应用程序，该应用程序将获取手机的当前位置并将其显示为地图上的标记。我正在使用具有不同类型安卓版本的设备。它在棒棒糖中工作正常并显示我当前的位置，但它不适用于其他版本，它只显示地图。它没有为我提供错误消息，所以我不确定发生了什么。

这是我用来获取当前位置的代码：

public void getLocation() {
try {
_locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
isGPSEnabled = _locationManager.isProviderEnabled(_locationManager.GPS_PROVIDER);
isNetworkEnabled = _locationManager.isProviderEnabled(_locationManager.NETWORK_PROVIDER);
if (_locationManager.getAllProviders().contains(LocationManager.GPS_PROVIDER))
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}_locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
if (_locationManager.getAllProviders().contains(LocationManager.NETWORK_PROVIDER))
_locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
// Ask for update
Location mobileLocation = _locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (mobileLocation != null) {
onLocationChanged(mobileLocation);
}
Location netLocation = _locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (netLocation != null) {
onLocationChanged(netLocation);
}
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void onLocationChanged(Location userLocation) {
if (userLocation == null) {
Log.e(TAG, "NO Internet");
return;
}
_longitude = userLocation.getLongitude();
_latitude = userLocation.getLatitude();
if (marker != null) {
marker.remove();
}
marker = mMap.addMarker(new MarkerOptions().position(new LatLng(_latitude, _longitude)).title("I'm Here"));
String cityName = null;
Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
List<Address> addresses;
try {
addresses = gcd.getFromLocation(userLocation.getLatitude(), userLocation.getLongitude(), 1);
if (addresses.size() > 0)
cityName = addresses.get(0).getLocality();
} catch (IOException e) {
e.printStackTrace();
}
String fullLocation = "Longitude : " + userLocation.getLongitude() + "nLatitude : " + userLocation.getLatitude() + "nnMy Current City is: " + cityName;
Log.e(TAG, "location : " + fullLocation);
}

谢谢！

Answer 1

试试这个答案。有时 getLastKnownLocation(( 返回 null。因此，您还必须添加位置更新请求。

Answer 2

对于棉花糖及以上版本，您必须明确请求用户许可。您可以使用此代码来实现它

private void RequestAllPermissions() {
String[] PERMISSIONS = {Manifest.permission.CAMERA, Manifest.permission.RECEIVE_SMS, Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.INTERNET, Manifest.permission.CALL_PHONE, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.WRITE_CONTACTS};
if (!hasPermissions(this, PERMISSIONS)) {
ActivityCompat.requestPermissions(this, PERMISSIONS, REQUESTCODE_PERMISSION_ALL);
} else
}
public static boolean hasPermissions(Context context, String... permissions) {
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) {
for (String permission : permissions) {
if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
return false;
}
}
}
return true;
}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case REQUESTCODE_PERMISSION_ALL: {
boolean allpermissiongranted = true;
if (grantResults.length > 0) {
for (int i = 0; i < permissions.length; i++) {
if (grantResults[i] != PackageManager.PERMISSION_GRANTED) {
allpermissiongranted = false;
break;
}
}
} else
allpermissiongranted = false;
if (allpermissiongranted) {
//do task
} else {
new SweetAlertDialog(mContext, SweetAlertDialog.WARNING_TYPE)
.setTitleText("Permission Not Granted")
.setContentText("Kindly grant all requested permission to proceed.")
.setConfirmText("Request")
.setConfirmClickListener(new SweetAlertDialog.OnSweetClickListener() {
@Override
public void onClick(SweetAlertDialog sDialog) {
sDialog.dismissWithAnimation();
RequestAllPermissions();
}
})
.setCancelText("Exit")
.setCancelClickListener(new SweetAlertDialog.OnSweetClickListener() {
@Override
public void onClick(SweetAlertDialog sweetAlertDialog) {
sweetAlertDialog.dismissWithAnimation();
finish();
}
})
.show();
}
}