我正在尝试使用此代码获取当前位置，它在启动应用程序并将其带到前台时有效。吐司在这两种情况下都会出现，但除此之外，它们不会出现。谁能告诉我我在哪里搞砸了？
public class LocationFragment extends Fragment implements GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener, LocationListener {
double oldLon,oldLat;
private static final String TAG = MainActivity.class.getSimpleName(); // LogCat tag
private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 1000;
private static final int MY_PERMISSIONS_REQUEST_FINE_LOCATION = 100;
private Location mLastLocation;
private GoogleApiClient mGoogleApiClient;
private FusedLocationProviderClient mFusedLocationClient;
private LocationRequest mLocationRequest;
// Location updates intervals in sec
private static int UPDATE_INTERVAL = 10000; // 10 sec
private static int FATEST_INTERVAL = 5000; // 5 sec
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
// First we need to check availability of play services
if (checkPlayServices()) {
buildGoogleApiClient();
createLocationRequest();
}
}
@Override
public void onDetach() {
mCallback = null; // => avoid leaking
super.onDetach();
}
public interface InterfaceTextClicked {
public void sendText(String text);
}
private boolean checkPermission(){
if(ActivityCompat.checkSelfPermission(getContext(),
ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED){
System.out.println("We have been granted.");
return true;}
else return false;
}
private void requestPermission(){
ActivityCompat.requestPermissions(getActivity(),new String[]
{ACCESS_FINE_LOCATION},MY_PERMISSIONS_REQUEST_FINE_LOCATION);
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_FINE_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay!
System.out.println("Permission Granted!");
} else {
// permission denied, boo!
System.out.println("Permission Denied!");
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
if(shouldShowRequestPermissionRationale(ACCESS_FINE_LOCATION)){
new AlertDialog.Builder(getActivity())
.setMessage("Permission needed to access your location.")
.setPositiveButton("OK", new DialogInterface.OnClickListener(){
@Override
public void onClick(DialogInterface dialog,int which){
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
requestPermissions(new String[]{ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_FINE_LOCATION);
}
}
})
.setNegativeButton("Cancel", null)
.create()
.show();
return;
}
}
}
// return;
}
}
}
private void displayLocation(){
System.out.println("Inside displayLocation");
requestPermission();
if(checkPermission()){
mLastLocation = LocationServices.FusedLocationApi
.getLastLocation(mGoogleApiClient);
}
if (mLastLocation != null) {
double latitude = mLastLocation.getLatitude();
double longitude = mLastLocation.getLongitude();
System.out.println("Location1: "+latitude+" "+longitude);
if(Double.compare(oldLat,latitude)==0 || Double.compare(oldLon,longitude)==0){
Toast.makeText(getContext(), "Location didn't change! "+latitude+ " "+ longitude,
Toast.LENGTH_LONG).show();
}else{
Toast.makeText(getContext(), "Location changed! NEW: "+latitude+ " "+ longitude+" OLD: "+oldLat+ " "+oldLon,
Toast.LENGTH_LONG).show();
}
// mCallback.sendText(latitude+" "+longitude);
oldLon = longitude;
oldLat = latitude;
} else {
System.out.println("Couldn't get coordinates");
if(mGoogleApiClient.isConnected()){
System.out.println("Client connected");
}else{
System.out.println("Client NOT connected");
}
}
}
/**
* Creating google api client object
* */
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(getContext())
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API).build();
}
/**
* Method to verify google play services on the device
* */
private boolean checkPlayServices() {
GoogleApiAvailability googleAPI = GoogleApiAvailability.getInstance();
int resultCode = googleAPI.isGooglePlayServicesAvailable(getContext());
if (resultCode != ConnectionResult.SUCCESS) {
if(googleAPI.isUserResolvableError(resultCode)){
googleAPI.getErrorDialog(getActivity(),resultCode,
PLAY_SERVICES_RESOLUTION_REQUEST).show();
} else {
Toast.makeText(getContext(),
"This device is not supported.", Toast.LENGTH_LONG)
.show();
getActivity().finish();
}
return false;
}
return true;
}
@Override
public void onStart() {
super.onStart();
if (mGoogleApiClient != null) {
mGoogleApiClient.connect();
}
}
@Override
public void onResume() {
super.onResume();
if (mGoogleApiClient != null && !mGoogleApiClient.isConnected()) {
mGoogleApiClient.connect();
}
checkPlayServices();
}
@Override
public void onStop() {
super.onStop();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
/**
* Creating location request object
* */
protected void createLocationRequest() {
mLocationRequest = LocationRequest.create();
mLocationRequest.setInterval(UPDATE_INTERVAL);
mLocationRequest.setFastestInterval(FATEST_INTERVAL);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); }
/**
* Starting the location updates
* */
protected void startLocationUpdates() {
System.out.println("Inside startLocationUpdates");
requestPermission();
if(checkPermission()){
if ((mGoogleApiClient != null) && (mGoogleApiClient.isConnected())){
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
}
}
/**
* Google api callback methods
*/
@Override
public void onConnectionFailed(ConnectionResult result) {
Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = "
+ result.getErrorCode());
}
@Override
public void onConnected(Bundle arg0){
startLocationUpdates();
// Once connected with google api, get the location
displayLocation();
}
@Override
public void onConnectionSuspended(int arg0) {
mGoogleApiClient.connect();
}
@Override
public void onPause() {
super.onPause();
stopLocationUpdates();
}
/**
* Stopping location updates
*/
protected void stopLocationUpdates() {
if ((mGoogleApiClient != null) && (mGoogleApiClient.isConnected())) {
LocationServices.FusedLocationApi.removeLocationUpdates(
mGoogleApiClient, this);
}
}
@Override
public void onLocationChanged(Location location) {
// Assign the new location
mLastLocation = location;
Toast.makeText(getContext(), "******Location changed!",
Toast.LENGTH_SHORT).show();
// Displaying the new location on UI
displayLocation();
}
}
很抱歉在那里放了这么多代码，我认为我的错误可能在任何地方，所以不想删掉任何东西。
日志显示以下内容：
10-14 01:10:27.408 14485-14485/com.android.wy.parkingauthoritytickingsystem I/System.out: Inside startLocationUpdates
10-14 01:10:27.536 14485-14485/com.android.wy.parkingauthoritytickingsystem I/System.out: We have been granted.
10-14 01:10:27.610 14485-14485/com.android.wy.parkingauthoritytickingsystem I/System.out: Inside displayLocation
10-14 01:10:27.617 14485-14485/com.android.wy.parkingauthoritytickingsystem I/System.out: We have been granted.
10-14 01:10:27.641 14485-14485/com.android.wy.parkingauthoritytickingsystem I/System.out: Location1: 40.4868602 -74.4388156
我没有看到您的代码有任何明显的问题，尽管它通过已弃用的位置 API 版本而不是新的 FusedLocationProviderClient 接口进行 API 调用。
当您声明新样式FusedLocationProviderClient时：
private FusedLocationProviderClient mFusedLocationClient;
你从不初始化它或在运行时使用它;而是通过FusedLocationApi（旧方法）调用它：
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
您可以尝试使用新的 API，它具有稍微强大的接口，以阐明您的问题。您可以使用以下方法获取新的 API 接口：
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
然后，您只需要在附加侦听器之前根据文档调整您的类以添加onLocationAvailability回调：
mFusedLocationClient.requestLocationUpdates(mLocationRequest,
mLocationCallback,
null /* Looper */);