我想要在片段中使用MapView。 這似乎很簡單...我仍然不明白!ViewPager中的MapFragment NullPointer:空對象上的'void maps.ad.y.v()'參考
我啓動應用程序時得到這個錯誤:
顯示java.lang.NullPointerException:嘗試上的空對象引用調用接口方法 '空隙maps.ad.yv()'
我有一個ViewPager活動:MainActivity
public class MainActivity extends AppCompatActivity {
private SectionsPagerAdapter mSectionsPagerAdapter;
private ViewPager mViewPager;
//...onCreate(), etc
public class SectionsPagerAdapter extends FragmentPagerAdapter {
//...
@Override
public Fragment getItem(int position) {
if (position == 0) {
return ClassicFragment.newInstance(position + 1);
// no problem with this one
} else if (position == 1) {
return MyMapFragment.newInstance(position + 1);
// here is my problem
}
}
}
}
而且2片段。 (一個簡單的,和一個帶有地圖) 我不設法做正確的片段:MyMapFragment
public class MyMapFragment extends SupportMapFragment implements OnMapReadyCallback {
View rootView;
private MapView mapView;
private GoogleMap googleMap;
public MyMapFragment() {
}
public static MyMapFragment newInstance(int sectionNumber) {
MyMapFragment fragment = new MyMapFragment();
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_map, container, false);
return rootView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
mapView = (MapView) rootView.findViewById(R.id.map);
mapView.onCreate(savedInstanceState);
mapView.onResume();
mapView.getMapAsync(this);//when you already implement OnMapReadyCallback in your fragment
}
@Override
public void onMapReady(GoogleMap map) {
googleMap = map;
}
}
最後,這裏是爲MyMapFragment的XML(fragment_map.xml)。
<LinearLayout 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"/>
</LinearLayout>
任何想法我做錯了什麼?
http://stackoverflow.com/a/35496677/1584654 – GVillani82
@ GVillani82我也嘗試這個解決辦法,但得到了同樣的確切的錯誤:( – Fundhor
我會建議使用MapView的,而不是雙重嵌套片段。這可能也無意中解決你的問題 – Orbit