从ViewPager的片段中获取GoogleMap

Question

我正试图GoogleMap从a Fragment的第二页获取对象ViewPager,其内容是给出的FragmentPagerAdapter.

我ViewPager由两个页面组成:普通版面和Google地图.

我可以访问第一个布局:

View tempView = LayoutInflater.from(getApplication())
                .inflate(R.layout.start_activity, null);
tempTextView = (TextView) tempView.findViewById(R.id.timer);

这里一切都好.但我也想访问谷歌地图.
当地图在一个单独的活动中时,我可以让GoogleMap对象执行此操作:

map=((SupportMapFragment)getSupportFragmentManager()
    .findFragmentById(R.id.map)).getMap();

但现在上面的线回来了 null

问题是如何GoogleMap从片段中获取对象？

他们建议这样做(有些人说这有效),但它对我不起作用:

map = ((SupportMapFragment) getSupportFragmentManager()
      .findFragmentByTag("android:switcher:" + R.id.pager + ":1")).getMap();

我在这里提供代码.

Answer 1

我已经在这里找到了解决方案,但也会在这里发布,以便其他用户查看代码并且不会像我那样被困住数周.

MyPagerAdapter.java

public class MyPagerAdapter extends FragmentPagerAdapter
{
    private Context context;
    final LatLng    YEREVAN = new LatLng(40.181, 44.513);

    public MyPagerAdapter(FragmentManager fm, Context context)
    {
        super(fm);
        this.context = context;
    }

    @Override
    public Fragment getItem(int position)
    {
        switch (position)
        {
            case 0:
                return new MyFragment();
            case 1:
                return MyMapFragment.newInstance(YEREVAN);
        }
        return null;
    }

    @Override
    public int getCount()
    {
        return 2;
    }

    @Override
    public CharSequence getPageTitle(int position)
    {
        Locale l = Locale.getDefault();
        switch (position)
        {
            case 0:
                return context.getString(R.string.start).toUpperCase(l);
            case 1:
                return context.getString(R.string.map).toUpperCase(l);
        }
        return null;
    }
}

MyMapFragment.java

public class MyMapFragment extends SupportMapFragment
{
    private LatLng  latLon;

    public MyMapFragment()
    {
        super();
    }

    public static MyMapFragment newInstance(LatLng position)
    {
        MyMapFragment frag = new MyMapFragment();
        frag.latLon = position;
        return frag;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        View v = super.onCreateView(inflater, container, savedInstanceState);
        initMap();
        return v;
    }

    private void initMap()
    {
        UiSettings settings = getMap().getUiSettings();
        settings.setAllGesturesEnabled(false);
        settings.setMyLocationButtonEnabled(false);

        getMap().moveCamera(CameraUpdateFactory.newLatLngZoom(latLon, 16));
        getMap().addMarker(new MarkerOptions().position(latLon).icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
    }
}