重新开放谷歌地图停止我的应用程序

Question

我有两个片段。通过点击第一个片段按钮，第二个片段即谷歌地图将打开。

第一次所有的事情都是正确的，但如果我回来再次单击程序将停止。

地图片段代码为打击：

public class map extends Fragment implements OnMapReadyCallback { 
    private GoogleMap mMap; 
    private double lat; 
    private double att; 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     View view=inflater.inflate(R.layout.map,container,false); 

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

     return view; 
    } 

    @Override 
    public void onStart() { 
     super.onStart(); 

     if (getArguments() != null) { 
      lat= getArguments().getDouble("LAT"); 
      att=getArguments().getDouble("ATT"); 
      Toast.makeText(getActivity(),String.valueOf(att),Toast.LENGTH_LONG).show(); 
      MapFragment mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.map); 
      mapFragment.getMapAsync(this); 
     } 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
    } 

    @Override 
    public void onAttach(Context context) { 
     super.onAttach(context); 
    } 
    @Override 
    public void onMapReady(GoogleMap googleMap) { 


     // Add a marker in Sydney and move the camera 
     LatLng sydney = new LatLng(lat, att); 
     CameraPosition googlePlex = CameraPosition.builder() 
       .target(new LatLng(lat,att)) 
       .zoom(16).build(); 
     googleMap.addMarker(new MarkerOptions().position(sydney)); 
     googleMap.moveCamera(CameraUpdateFactory.newCameraPosition(googlePlex)); 

    } 
} 

和主要活动是：

public class MainActivity extends AppCompatActivity implements onclicklistener{ 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     if(findViewById(R.id.firstpage)!=null) 
     { 
      if(savedInstanceState!=null) 
       return; 
      firstpage startpage=new firstpage(); 
      FragmentManager fm=getFragmentManager(); 
      FragmentTransaction ft=fm.beginTransaction(); 


      ft.add(R.id.firstpage,startpage); 
      ft.commit(); 


     } 
    } 
@Override 
    public void onclickbutton(String index) { 
    try{ map newmap=new map(); 
      Bundle args = new Bundle(); 
      args.putDouble("LAT",32.657892); 
      args.putDouble("ATT",51.668643); 
     FragmentManager fm=getFragmentManager(); 
     FragmentTransaction ft=fm.beginTransaction(); 
     newmap.setArguments(args); 
     ft.addToBackStack(null); 
      ft.replace(R.id.firstpage,newmap); 

      ft.commit();} 
      catch (Exception e){Toast toast = Toast.makeText(this, "error", Toast.LENGTH_SHORT);} 
     } 

    @Override 
    public void onBackPressed() { 
     if (getFragmentManager().getBackStackEntryCount() > 0){ 
      getFragmentManager().popBackStack(); 
     } else { 
      super.onBackPressed(); 
     } 
    } 

    } 

第一次运行完全正常，但如果我再次点击程序将停止。请指导我。

Answer 1

它解决了。

我添加以下代码：

@Override 
    public void onDetach() { 
     Fragment fragment = (getFragmentManager().findFragmentById(R.id.map)); 
     FragmentTransaction ft = getActivity().getFragmentManager().beginTransaction(); 
     ft.remove(fragment); 
     ft.commit(); 
     super.onDetach(); 
    }