单击AndId Back按钮后包含两个片段的java销毁活动

Question

问题解决了

问题: 我有问题，我找不到任何解决办法。我有一个活动，它包含两个片段。这两个片段都显示了google maps v2，我通过两个ActionBar标签在屏幕上显示它们

当我想回到之前的活动时，问题就出现了。当我点击安卓后退按钮时，我的整个应用程序都关闭了，显示我的应用程序被停止了

我应该向代码中添加什么来删除此错误

解决方案：

地图和你的活动。爪哇

import 安卓.app.ActionBar;
import 安卓.app.Activity;
import 安卓.app.Fragment;

import 安卓.app.FragmentManager;
import 安卓.app.FragmentTransaction;
import 安卓.os.Bundle;
import 安卓.util.Log;
import 安卓.widget.Button;



import com.google.安卓.gms.maps.MapFragment;


public class Maps_Activity extends Activity {

    public static FragmentManager manager;
    Fragment fragmentTab1 = new Medical_Shops_Map();
    Fragment fragmentTab2 = new Medical_Clicnics_Map();
    Button Medical_Shops_Button, Medical_Clinics_Button;
    ActionBar actionBar ;

    @Override
    public void onCreate(Bundle arg0) {
        super.onCreate(arg0);
        setContentView(R.layout.activity_maps_);


        manager = getFragmentManager();

        actionBar=getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        ActionBar.Tab tab1=actionBar.newTab();
        tab1.setText("Apteki 24H/7");
        tab1.setTabListener(new MyTabsListener(fragmentTab1));

        ActionBar.Tab tab2=actionBar.newTab();
        tab2.setText("Przychodnie Lekarskie");
        tab2.setTabListener(new MyTabsListener(fragmentTab2));

        actionBar.addTab(tab1);
        actionBar.addTab(tab2);


    }

    protected class MyTabsListener implements ActionBar.TabListener {

        private Fragment fragment;

        public MyTabsListener(Fragment fragment) {
            this.fragment = fragment;

        }

        public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
        }

        public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
            ft = manager.beginTransaction();
            ft.replace(R.id.map_container, fragment);
            ft.commit();
            Log.e("Activity", "Fragment replace");
        }

        public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
            // some people needed this line as well to make it work:

            MapFragment mMap2 = ((MapFragment) Maps_Activity.manager.findFragmentById(R.id.map));
            ft = manager.beginTransaction();
            if(mMap2!=null)
            {
                ft.remove(mMap2);
                ft.commit();
                Log.e("Activity", "Mapa_fragment destroy");
            }
            else
            {
                MapFragment mMap1 = ((MapFragment) Maps_Activity.manager.findFragmentById(R.id.map1));
                ft.remove(mMap1);
                ft.commit();
                Log.e("Activity", "Mapa_fragment2 destroy");
            }
        }

    }

}

其中一个片段：

   import 安卓.os.Bundle;
import 安卓.app.Fragment;
import 安卓.support.v4.app.FragmentActivity;
import 安卓.util.Log;
import 安卓.view.LayoutInflater;
import 安卓.view.View;
import 安卓.view.ViewGroup;
import 安卓.widget.LinearLayout;
import 安卓.widget.Toast;

import com.google.安卓.gms.maps.CameraUpdateFactory;
import com.google.安卓.gms.maps.GoogleMap;
import com.google.安卓.gms.maps.GoogleMapOptions;
import com.google.安卓.gms.maps.MapFragment;
import com.google.安卓.gms.maps.OnMapReadyCallback;
import com.google.安卓.gms.maps.model.LatLng;
import com.google.安卓.gms.maps.model.MarkerOptions;


public class Medical_Clicnics_Map extends Fragment implements OnMapReadyCallback {



    private static View view;

    private static GoogleMap mMap2;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        view =  inflater.inflate(R.layout.medical__clicnics__map, container, false);

        setUpMapIfNeeded();

        return view;
    }


    public void setUpMapIfNeeded() {

            MapFragment mMap2 = ((MapFragment) Maps_Activity.manager
                    .findFragmentById(R.id.map1));
            mMap2.getMapAsync(Medical_Clicnics_Map.this);

    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        Log.d("Activity", "Map ready");
        googleMap.setMyLocationEnabled(true);
        LatLng sydney = new LatLng(-33.867, 151.206);
        googleMap.addMarker(new MarkerOptions()
                .title("Sydney")
                .snippet("The most populous city in Australia.")
                .position(sydney));
    }



}

也许这段代码对某些人会有帮助；）