I am using Google Map in my project, and I created an Activity with the map fragment inside. After map was successfully loaded, if I swipe a little bit and hit Back button quickly (May be when the map is still moving), the Map Activity will reload itself. I tracked its life cycle methods and found that it restarted from OnCreate method. This occurs sometimes, not always.
If I change the launch mode of the activity to "singleTask", it works fine. However, it is not recommended to use singleTask Mode generally, based on official documentation.
Can anyone please help to explain what happens under this scene and provide the best way to fix it? Thanks.
The XML of the activity is:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.alcatel.movetime.ui.view.map.MapActivity"
android:clickable="true">
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"
/>
</RelativeLayout>
And the Activity is also pretty simple:
public class MapActivity extends AppCompatActivity implements OnMapReadyCallback {
GoogleMap map;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
#Override
public void onMapReady(GoogleMap googleMap) {
map = googleMap;
final LatLng kidPosition = new LatLng(31.2, 121.5);
CameraPosition target;
target = CameraPosition.builder().target(kidPosition).zoom(14).build();
map.animateCamera(CameraUpdateFactory.newCameraPosition(target));
}
}
Related
Iam practicing on Google Maps for android development. I have followed the steps as in https://developers.google.com/maps/documentation/android-api/map-with-marker
While when playing the app I got the screen like this below, no marker and the map cannot show any thing
My code as following:
public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
#Override
public void onMapReady(GoogleMap googleMap) {
// Add a marker in Sydney, Australia,
// and move the map's camera to the same location.
LatLng sydney = new LatLng(-33.852, 151.211);
googleMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
googleMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
}
******** . XML Layout ************
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.ae.map_04.MainActivity">
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment" />
</LinearLayout>
This is most likely an API Key issue. You can find some guidance here: Android Studio - Google map still blank on real Android device on release apk
If that does not work, try a new API Key.
My application has 3 tabs and in one of them I want to display a map(HERE MAPS, not Google Maps). I was able to get the map to work perfectly in an Activity, but in Fragment Class when I try to cast the Fragment view to the MapFragment an error is thrown.
MapFragment mapFragment = (MapFragment)
getFragmentManager().findFragmentById(R.id.mapfragment);
Error:
Inconvetible types: cannot cast android.support.v4.app.support to com.here.android.mpa.mapping.MapFragment
Please correct me if Im wrong, but the reason for this to happen is because we can´t use android.app.Fragment(used to display the map, as instructed in HERE MAPS DOC) in an android.support.v4.app.Fragment(used for the TabsLayout).
I found many questions related to this error using Google Maps. but just two(first,second)about the same error when using HERE MAPS, and none really helped to solve the problem.
In google Maps you can use SupportMapFragment(), but this mehod only works for Google Maps. Is there any solution for this using Here Maps? maybe a different approach to reach the same goal? or am I missing something when implementing this Here Maps in a TabLayout?
Any help will be appreciated!
My code:
MapFragment.java
public class Map extends Fragment {
public Map() {}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_map, container, false);
MapFragment mapFragment = (MapFragment)
getFragmentManager().findFragmentById(R.id.mapfragment);
mapFragment.init(new OnEngineInitListener() {
#Override
public void onEngineInitializationCompleted(
OnEngineInitListener.Error error) {
if (error == OnEngineInitListener.Error.NONE) {
com.here.android.mpa.mapping.Map map = mapFragment.getMap();
} else {
System.out.println("ERROR: Cannot initialize MapFragment");
}
}
};
return view;
}
fragment_map.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.modulos.tabsMenu.Config">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:id="#+id/mapFragmentContainer"
android:layout_weight="1"
android:orientation="vertical"
android:gravity="center"
android:background="#aaa" >
<fragment
class="com.here.android.mpa.mapping.MapFragment"
android:id="#+id/mapfragment"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="vertical"
android:gravity="center"
android:background="#aaa" >
<!-- other things here -->
</LinearLayout>
</FrameLayout>
Since the HERE Maps SDK only works with API Level 15 and above, there's no support for compatibility fragments (that you mainly need when you target lower API levels).
In some cases you still want to deal with support fragment even if you have Android 4 or newer as target, in those cases you have to use the the MapView of the HERE SDK and embedded it in your layout on your own.
See this code example where also MapView is used: https://tcs.ext.here.com/sdk_examples/MapDownloader.zip
So, it will look like this:
Add in your layout the MapView:
<com.here.android.mpa.mapping.MapView
android:id="#+id/ext_mapview"
android:visibility="visible"
android:layout_width="match_parent"
android:layout_height="match_parent" />
And then in your code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mapView = (MapView) findViewById(R.id.ext_mapview);
MapEngine.getInstance().init(this, engineInitHandler);
}
private OnEngineInitListener engineInitHandler = new OnEngineInitListener() {
#Override
public void onEngineInitializationCompleted(Error error) {
if (error == Error.NONE) {
map = new Map();
mapView.setMap(map);
// more map initial settings
} else {
Log.e(TAG, "ERROR: Cannot initialize MapEngine " + error);
}
}
};
#Override
public void onResume() {
super.onResume();
MapEngine.getInstance().onResume();
if (mapView != null) {
mapView.onResume();
}
}
#Override
public void onPause() {
if (mapView != null) {
mapView.onPause();
}
MapEngine.getInstance().onPause();
super.onPause();
}
It's important that you handle the MapEngine and MapView Pause and Resume, otherwise you would get poor performance results.
Surely is a silliness ask this, but do you check if are you using MapFragment from the right package?
You must be using this class com.here.android.mpa.mapping.MapFragment, maybe by error you import this one com.google.android.gms.maps.MapFragment.
I having trouble implementing Google Map in Fragment.
This is my the part of my fragment class:
public class FragmentStoreFinderMap extends Fragment implements OnMapReadyCallback {
// Google Map
private GoogleMap googleMap;
private int i;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
googleMap = ((SupportMapFragment)getActivity().getSupportFragmentManager().findFragmentById(
R.id.map)).getMapAsync(this);
I am getting an error in getMapAsync(this). I tells Incompatible type.
it says:
required: com.google.android.gms.map.GoogleMap
found: void
BTW here is my xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<fragment class="com.google.android.gms.maps.SupportMapFragment"
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
In your XML layout you should do like this
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.gms.maps.MapView
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
inside your fragment implement this
private MapView mapView;
private GoogleMap googleMap;
override onCreateView if there is no onCreateView just like the code below
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.your_layout, container, false);
}
override onViewCreated() inside that
onViewCreated() put this
mapView = (MapView) view.findViewById(R.id.map);
mapView.onCreate(savedInstanceState);
mapView.onResume();
mapView.getMapAsync(this);//when you already implement OnMapReadyCallback in your fragment
when you already implement OnMapReadyCallback in your fragment put this/code like this
#Override
public void onMapReady(GoogleMap map) {
googleMap = map;
}
hope this helps you.
After a few overheats in my head, thanks to this post and https://stackoverflow.com/a/34732804/3925554, I would say that currently there are two ways of adding a MapFragment to your app:
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
class="com.google.android.gms.maps.SupportMapFragment"
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
By this way, you have to use a standard fragment and implement this inside. Actually you are inserting a fragment into another:
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
SupportMapFragment supportMapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map);
supportMapFragment.getMapAsync(this);
}
The other way would be extending the real SupportMapFragment and implement it in this manner without the need of an xml:
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
getMapAsync(this);
}
And they work without having to set a layout in onCreateView neither call mapView.onCreate(savedInstanceState); and mapView.onResume(); manually inside onViewCreated(), what is not recommended anyway.
Hope it helps!
SupportMapFragment mMapFragment = SupportMapFragment.newInstance();
FragmentTransaction fragmentTransaction =
getChildFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.flMap, mMapFragment);
fragmentTransaction.commit();
mMapFragment.getMapAsync(this);
Your code is returning this error because getMapAsync() does not return anything. If you look at the documentation for this function:
public void getMapAsync (OnMapReadyCallback callback)
Sets a callback object which will be triggered when the GoogleMap
instance is ready to be used.
Note that:
This method must be called from the main thread. The callback will be
executed in the main thread. In the case where Google Play services is
not installed on the user's device, the callback will not be triggered
until the user installs it. In the rare case where the GoogleMap is
destroyed immediately after creation, the callback is not triggered.
The GoogleMap object provided by the callback is non-null.
OnMapReadyCallback is an interface that needs implemented and passed to through this function. Nothing is currently assigned to your googleMap variable you should instead set its value in this block of code which implements OnMapReadyCallback
#Override
public void onMapReady(GoogleMap googleMap) {
this.googleMap = googleMap;
}
This code should be in your Fragment somewhere. Since your Fragment already implements this interface you do pass it in as this.
I move my application eclipse to android studio. My code works perfect on Eclipse but on Android studio
mapView = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
return null
my xml is here
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
xmlns:ads="http://schemas.android.com/apk/res-auto"
>
<com.google.android.gms.ads.AdView
android:id="#+id/adMob"
android:layout_width="fill_parent"
android:layout_height="70dp"
android:layout_alignParentBottom="true"
ads:adSize="BANNER"
ads:adUnitId="#string/admob_unit_id" />
<fragment
android:id="#+id/map"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
class="com.google.android.gms.maps.SupportMapFragment"/>
</LinearLayout>
why it return null?
I searched and compileSdkVersion 21 cause it. But if I change it 19 still return null
getMap() is not guaranteed to return a map instance. Use getMapAsync(OnMapReadyCallback) where the callback will be invoked once the map is ready and you're guaranteed it won't be null. This is available since Google Play Services library v6.5.
When using this approach get rid of your mapView variable, the callback will receive a map reference anyway. Also note that SupportMapFragment is not MapView is not GoogleMap (I'm referring to the misnamed variable here, be careful.).
EDIT: Suggested solution:
public class MainActivity extends ActionBarActivity {
SupportMapFragment mMapFragment;
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_main);
mMapFragment = getSupportFragmentManager().findFragmentById(R.id.map);
// etc.
}
public void doSomethingWithMap() {
mMapFragment.getMapAsync(new OnMapReadyCallback() {
#Override
public void onMapReady(GoogleMap googleMap) {
// do whatever you need with the map
}
});
}
}
The point is when you need to access the map, you ask the fragment for it, and it will be delivered to you via a callback.
I'm trying to use google map in fragment, but I meet a problem I don't understand.
I don't arrive to load the map in this line :
gMap = ((SupportMapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
This line seems to return always null...
I tried to use MapFragment inseatd of SupportMapFragment, but it's not possible.
How to resolve it ?
To explain why i want to show it in a fragment, it's because i'm using a navigationdrawer, and one of my item needs to show the map.
thx,
EDIT : My xml :
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.MapFragment"/>
I think you should call with getsupportFragmentManager not with getFragmentManager otherwise it will return null always
If you are using SupportMapFragment, you need to change your layout!
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.SupportMapFragment"/>
This is a basic example using SupportMapFragment:
public class MainActivity extends ActionBarActivity implements OnMapReadyCallback{
private SupportMapFragment map;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
map.getMapAsync(this);//remember getMap() is deprecated!
}
#Override
public void onMapReady(GoogleMap map) {
map.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(47.17, 27.5699), 16));
map.addMarker(new MarkerOptions() .icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)).anchor(0.0f, 1.0f) // Anchors the marker on the bottom left
.position(new LatLng(47.17, 27.5699))); //Iasi, Romania
map.setMyLocationEnabled(true);
}
}
and change the reference in your layout:
<fragment
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment" />
I dont think it is possible as google map contains a < fragment> tag. See here why:
Note: You cannot inflate a layout into a fragment when that layout includes a . Nested fragments are only supported when added to a fragment dynamically.
Some people in SO however managed to show map in a fragment, but the solution was hacky.