Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
309 views
in Technique[技术] by (71.8m points)

android - MapFragment or MapView getMap() returns null on Lollipop

I've been using Google Maps API v2 for a long time on Android 4.x versions without a problem. Now I installed latest Lollipop build on my Nexus devices (5 and 7) trying to materialize the app.

I'd like to point out that everything is ok on KitKiat and the problem I'm describing is poping up only on Lollipop.

In my XML source code I'm using MapFragment (Google Play Services library version 6.1.11).

<fragment android:id="@+id/map"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:name="com.google.android.gms.maps.MapFragment"/>

In Java code I'm overriding OnPause() method to reach map:

GoogleMap map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

At this line it throws NullPointerException. In debugger app is able to find fragment, however it's not able to return GoogleMap. I've also tried to use MapView. It also throws null. The weirdest thing for me is that map loads without a problem on app itself but in code I cant reach it to work with it.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

I had exactly the same problem but this is what worked for me:

Replace this...

GoogleMap map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

with this...

GoogleMap map = getMapFragment().getMap();

then slip this bad boy in and give it a whirl...

private MapFragment getMapFragment() {
    FragmentManager fm = null;

    Log.d(TAG, "sdk: " + Build.VERSION.SDK_INT);
    Log.d(TAG, "release: " + Build.VERSION.RELEASE);

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        Log.d(TAG, "using getFragmentManager");
        fm = getFragmentManager();
    } else {
        Log.d(TAG, "using getChildFragmentManager");
        fm = getChildFragmentManager();
    }

    return (MapFragment) fm.findFragmentById(R.id.map);
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...