如何解决无法在 android studio 上打开谷歌地图获取位置
基本上我注意到应用程序中有这种奇怪的反应，我得到 location is null 但是如果我退出应用程序并打开谷歌地球地图，请求我的位置并重新进入应用程序，定位服务将正常工作，任何想法为什么会这样？
我确定问题不在权限上，因为我确实检查了这个并且它工作得很好，而且电话位置也被启用，这让我不明白为什么它会做出这样的反应
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater,@Nullable ViewGroup container,@Nullable Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.fragment_find_customer,container,false);
tableLayout = (TableLayout) v.findViewById(R.id.resultsTable);
tableLayout.setStretchAllColumns(true);
// tableLayout.setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
// Button searchNearby = v.findViewById(R.id.resultsTable);
// searchNearby.setonClickListener(new View.OnClickListener() {
// @Override
// public void onClick(View v) {
// searchRequest = new SearchRequest();
//
// }
// });
EditText editText = (EditText) v.findViewById(R.id.txtEditPostcodeSearch);
Button clear = (Button) v.findViewById(R.id.btnClearText);
clear.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View av) {
editText.setText("");
}
});
if (checkGoogleServices()) {
fusedLocationClient = LocationServices.getFusedLocationProviderClient(getContext());
}
Button searchButton = (Button) v.findViewById(R.id.btnSearchCustomer);
searchButton.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
EditText searchInput = (EditText) v.findViewById(R.id.txtEditPostcodeSearch);
String search = searchInput.getText().toString();
Log.d("SEARCH",search);
if (searchInput.getText().length() == 0) {
Toast.makeText(getContext(),"Please enter a search",Toast.LENGTH_LONG).show();
return;
}
searchRequest = new SearchRequest();
searchRequest.setTerm(search);
getLocation();
}
});
Button searchNearby = (Button) v.findViewById(R.id.btnSearchNearby);
searchNearby.setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
searchRequest = new SearchRequest();
getLocation();
}
});
//
// tableLayout = (TableLayout) findViewById(R.id.resultsTable);
// tableLayout.setStretchAllColumns(true);
//
// Button searchNearby = (Button) findViewById(R.id.btnSearchNearby);
// searchNearby.setonClickListener(new View.OnClickListener() {
// @Override
// public void onClick(View view) {
// searchRequest = new SearchRequest();
// getLocation();
// }
// });
return v;
}
protected boolean checkGoogleServices() {
GoogleApiAvailability ga = GoogleApiAvailability.getInstance();
int errorCode = ga.isGooglePlayServicesAvailable(getContext());
if (errorCode != SUCCESS && ga.isUserResolvableError(errorCode)) {
// ga.getErrorDialog(this,errorCode,1000).show();
Log.d("LOC","ERROR with location services");
return false;
}
return true;
}
private void getLocation() {
if (ContextCompat.checkSelfPermission(getContext(),Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
fusedLocationClient.getLastLocation()
.addOnSuccessListener(new OnSuccessListener<Location>() {
@RequiresApi(api = Build.VERSION_CODES.N)
@Override
public void onSuccess(Location location) {
// Got last kNown location. In some rare situations this can be null.
if (location != null) {
// Logic to handle location object
searchRequest.setLatitude(String.valueOf(location.getLatitude()));
searchRequest.setLongitude(String.valueOf(location.getLongitude()));
userLocation = location;
Log.d("lat",searchRequest.getLatitude());
Log.d("long",searchRequest.getLongitude());
doSearch();
} else {
Log.d("Location","Location is null");
}
}
})
.addOnFailureListener(new OnFailureListener() {
@RequiresApi(api = Build.VERSION_CODES.N)
@Override
public void onFailure(@NonNull Exception e) {
if (searchRequest != null && searchRequest.getTerm() != null) {
doSearch();
}
}
})
;
} else {
// You can directly ask for the permission.
// The registered ActivityResultCallback gets the result of this request.
requestPermissionLauncher.launch(Manifest.permission.ACCESS_COARSE_LOCATION);
}
}
@RequiresApi(api = Build.VERSION_CODES.N)
private void doSearch() {
View view = getActivity().getCurrentFocus();
if (view != null) {
InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getwindowToken(),0);
}
int rows = tableLayout.getChildCount();
if (rows > 0) {
tableLayout.removeViews(0,rows);
}
AppActivity a = (AppActivity) getActivity();
CustomerRepository customerRepository = new CustomerRepository(a.getApplication());
customerRepository.search(searchRequest).observe(getViewLifecycleOwner(),customers -> {
Log.d("Found",String.valueOf(customers.size()));
if (customers.size() == 0) {
Toast.makeText(getContext(),"No results found",Toast.LENGTH_LONG).show();
} else {
TableRow[] tableRows = new TableRow[customers.size()];
// calculate distance of each customer from user
for (int i = 0; i < customers.size(); i++) {
Customer customer = customers.get(i);
try {
Location customerLocation = new Location("customer");
customerLocation.setLatitude(Double.valueOf(customer.getLatitude()));
customerLocation.setLongitude(Double.valueOf(customer.getLongitude()));
customer.setdistance(userLocation.distanceto(customerLocation)*0.000621371f); // convert metres to miles
} catch (NumberFormatException e) {
e.printstacktrace();
} catch (NullPointerException e) {
e.printstacktrace();
customer.setdistance(0);
}
}
// sort by distance ascending
customers.sort((c,d) -> {
if (c.getdistance() < d.getdistance()) {
return -1;
} else if (c.getdistance() > d.getdistance()) {
return 1;
} else {
return 0;
}
});
for (int i = 0; i < customers.size(); i++) {
tableRows[i] = new TableRow(getContext());
tableRows[i].setId(i + 1);
tableRows[i].setLayoutParams(new TableRow.LayoutParams(
TableRow.LayoutParams.MATCH_PARENT,TableRow.LayoutParams.WRAP_CONTENT
));
tableRows[i].setPadding(0,20,80,20);
tableRows[i].setBackgroundResource(android.R.drawable.list_selector_background);
tableRows[i].setBackgroundResource(R.drawable.table_outline);
TextView customerText = new TextView(getContext());
customerText.setId(i + 111);
customerText.setText(customers.get(i).getName());
customerText.setTextColor(Color.BLACK);
customerText.setPadding(14,5,5);
customerText.setTextSize(16);
customerText.setMaxLines(3);
customerText.setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
customerText.setEllipsize(TextUtils.TruncateAt.END);
customerText.setWidth(200);
TextView text2 = new TextView(getContext());
text2.setId(i + 1111);
text2.setText(customers.get(i).getTown());
text2.setEms(4);
text2.setMaxLines(1);
text2.setTextSize(16);
text2.setTextColor(Color.BLACK);
text2.setTextAlignment(TextView.TEXT_ALIGNMENT_CENTER);
text2.setPadding(40,5);
TextView text3 = new TextView(getContext());
text3.setId(i + 11111);
text3.setText(customers.get(i).getType());
text3.setEms(4);
text3.setMaxLines(1);
text3.setTextColor(Color.BLACK);
text3.setTextAlignment(TextView.TEXT_ALIGNMENT_CENTER);
text3.setTextSize(16);
text3.setPadding(5,5);
TextView text4 = new TextView(getContext());
text4.setId(i + 111111);
text4.setText(String.valueOf(customers.get(i).getdistance()));
text4.setEms(6);
text4.setMaxLines(2);
text4.setTextColor(Color.BLACK);
text4.setTextAlignment(TextView.TEXT_ALIGNMENT_CENTER);
text4.setTextSize(16);
text4.setPadding(5,5);
tableRows[i].addView(customerText);
tableRows[i].addView(text2);
tableRows[i].addView(text3);
tableRows[i].addView(text4);
tableLayout.addView(tableRows[i],new TableLayout.LayoutParams(
TableLayout.LayoutParams.MATCH_PARENT,TableLayout.LayoutParams.WRAP_CONTENT
));
tableRows[i].setClickable(true);
String customerId = customers.get(i).getUuid().toString();
int finalI = i;
tableRows[i].setonClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
TableRow tr = (TableRow) view;
TextView s = (TextView) tr.getChildAt(0);
String r = s.getText().toString();
Toast.makeText(getContext(),r,Toast.LENGTH_SHORT).show();
Fragment addAppointmentWithExistingCustomerActivity = new AddAppointmentWithExistingCustomerFragment();
FragmentTransaction transaction = requireActivity().getSupportFragmentManager().beginTransaction();
Bundle addBundle = new Bundle();
addBundle.putString(CUSTOMER_ID,customerId);
addAppointmentWithExistingCustomerActivity.setArguments(addBundle);
// Replace whatever is in the fragment_container view with this fragment,// and add the transaction to the back stack if needed
transaction.replace(R.id.fragment_container,addAppointmentWithExistingCustomerActivity);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
});
}
}
});
}
解决方法
您不能简单地依赖最后位置，因为它可能为空...
您可以request location updates，而不是完全依赖最后位置，只要您的最后位置为空，并且在获得位置后停止位置更新（仅在您需要位置时停止更新） )
https://developer.android.com/training/location/request-updates
,if you want to access location even if the app is not in foreground,you need to set "Allow all time" in location permission settings.Also include below line in AndroidManifest file.
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
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