我正在装箱。当我安装应用程序然后打开它并允许位置访问权限但仅显示map时，我没有获得当前位置。重新打开应用程序后，当前位置显示。使用以下代码 -
public class MainActivity extends AppCompatActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {
LocationRequest mLocationRequest;
GoogleApiClient mGoogleApiClient;
LatLng latLng;
GoogleMap mMap;
SupportMapFragment mFragment;
Marker CurrentMarker;
private static final int PERMISSION_REQUEST_CODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
mFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mFragment.getMapAsync(this);
// Button request_permission = (Button)findViewById(R.id.request_permission);
//request_permission.setOnClickListener(this);
if (!checkPermission()) {
requestPermission();
} else {
Toast.makeText(this,"Permission already granted.",Toast.LENGTH_SHORT).show();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
//final int LOCATION_PERMISSION_REQUEST_CODE = 100;
// ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.ACCESS_COARSE_LOCATION},
// LOCATION_PERMISSION_REQUEST_CODE);
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
mMap.setMyLocationEnabled(true);
buildGoogleApiClient();
mGoogleApiClient.connect();
}
private void buildGoogleApiClient() {
// TODO Auto-generated method stub
Toast.makeText(this, "buildGoogleApiClient", Toast.LENGTH_SHORT).show();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
@Override
public void onConnected(Bundle bundle) {
Toast.makeText(this, "Onconnection", Toast.LENGTH_SHORT).show();
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if(mLastLocation != null){
latLng = new LatLng(mLastLocation.getLatitude(), mLastLocation.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title("Current Location");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
CurrentMarker = mMap.addMarker(markerOptions);
}
mLocationRequest = new LocationRequest();
//mLocationRequest.setInterval(5000);
// mLocationRequest.setFastestInterval(3000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
@Override
public void onConnectionSuspended(int i) {
Toast.makeText(this,"onConnectionSuspended",Toast.LENGTH_SHORT).show();
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
Toast.makeText(this,"onConnectionFailed",Toast.LENGTH_SHORT).show();
}
@Override
public void onLocationChanged(Location location) {
if (CurrentMarker != null){
CurrentMarker.remove();
}
latLng = new LatLng(location.getLatitude(), location.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title("Current Position");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
CurrentMarker = mMap.addMarker(markerOptions);
Toast.makeText(this,"Location changed",Toast.LENGTH_SHORT).show();
CameraPosition cameraPosition = new CameraPosition.Builder().target(latLng).zoom(14).build();
mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
private boolean checkPermission(){
int result = ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION);
if (result == PackageManager.PERMISSION_GRANTED){
return true;
} else {
return false;
}
}
private void requestPermission(){
if (ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.ACCESS_FINE_LOCATION)){
Toast.makeText(this,"GPS permission allows us to access location data. Please allow in App Settings for additional functionality.",Toast.LENGTH_LONG).show();
} else {
ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},PERMISSION_REQUEST_CODE);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_CODE:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
} else {
}
break;
}
}
}
请告诉我如何在安装时获取位置，然后第一次打开它。使用我的源代码。
由于
答案 0 :(得分：0)
在marshmallow中，在用户允许在运行时访问应用程序之前，您无法获取位置。 用户许可位置权限重新启动您的活动
desc <TABLE NAME> ;
答案 1 :(得分：0)
为什么没有第一次出现：因为你在授予后没有处理。
你为什么第二次出现：因为你之前已经获得了许可。
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_CODE:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// TRY GETTING THE LOCATION HERE ON FIRST TIME (AFTER GRANTING)
Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
} else {}
break;
}
}