FireBase实时数据库在第二个视图上为空

我遇到了一个片段，它显示了一个带有Firebase实时数据库项目的Listview，通过一个适配器。当我第一次打开片段时，它会显示所有内容，但当我转到另一个片段并第二次打开第一个片段时，它将保持为空。如下图所示。FireBase实时数据库在第二个视图上为空

Problem with empty fragment

这是我的代码：

Tablayout片段：

public class Stand_Fragment extends Fragment { 

DatabaseReference mDatabase; 
Toolbar toolbar; 
TabLayout tabLayout; 
ViewPager viewPager; 
Stand_ViewPager standViewPager; 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    View View = inflater.inflate(R.layout.fragment_stand, container, false); 

    getActivity().setTitle("Stand"); 

    tabLayout = (TabLayout)View.findViewById(R.id.tabLayout_stand); 
    viewPager = (ViewPager) View.findViewById(R.id.viewPager_stand); 

    toolbar = (Toolbar) View.findViewById(R.id.toolbar_stand); 
    ((AppCompatActivity)getActivity()).setSupportActionBar(toolbar); 

    tabLayout = (TabLayout)View.findViewById(R.id.tabLayout_stand); 
    viewPager = (ViewPager) View.findViewById(R.id.viewPager_stand); 
    standViewPager = new Stand_ViewPager(getFragmentManager()); 
    standViewPager.addFragments(new StandBeker_Fragment(), "Beker"); 
    standViewPager.addFragments(new StandCompetitie_Fragment(), "Competitie"); 
    standViewPager.addFragments(new StandBeker_Fragment_Admin(), "Admin Beker"); 
    standViewPager.addFragments(new StandCompetitie_Fragment_Admin(), "Admin Competitie"); 

    tabLayout.setTabTextColors(ColorStateList.valueOf(Color.parseColor("#ffffff"))); 
    viewPager.setAdapter(standViewPager); 
    tabLayout.setupWithViewPager(viewPager); 

    return View; 
} 
}

片段，其示出了列表视图：

public class StandBeker_Fragment extends Fragment { 

private DatabaseReference mDatabaseRef; 
private List<ImageUpload> imgList; 
private ListView lv; 
private StandBeker_Adapter adapter; 
private ProgressDialog progressDialog; 

public StandBeker_Fragment(){ 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    final View View = inflater.inflate(R.layout.activity_image_list, container, false); 

    imgList = new ArrayList<>(); 
    lv = (ListView) View.findViewById(R.id.ListViewImage); 

    progressDialog = new ProgressDialog(getActivity()); 
    progressDialog.setMessage("Aan het laden..."); 
    progressDialog.show(); 

    mDatabaseRef = FirebaseDatabase.getInstance().getReference(StandBeker_Fragment_Admin.FB_DATABASE_PATH); 
    mDatabaseRef.addValueEventListener(new ValueEventListener() { 
     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      progressDialog.dismiss(); 

      for(DataSnapshot snapshot : dataSnapshot.getChildren()) { 
       ImageUpload img = snapshot.getValue(ImageUpload.class); 
         imgList.add(img); 
      } 
      adapter = new StandBeker_Adapter(getActivity(), R.layout.fragment_stand_beker, imgList); 
      lv.setAdapter(adapter); 
     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 
     } 
    }); 

    return View; 
} 
}

适配器类列表视图的：

public class StandBeker_Adapter extends ArrayAdapter<ImageUpload> { 
private Activity context; 
private int resource; 
private List<ImageUpload> listImage; 

public StandBeker_Adapter(@NonNull Activity context, @LayoutRes int resource, @NonNull List<ImageUpload> objects) { 
    super(context, resource, objects); 
    this.context = context; 
    this.resource = resource; 
    listImage = objects; 
} 

@NonNull 
@Override 
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) { 
    LayoutInflater inflater = context.getLayoutInflater(); 

    View v = inflater.inflate(resource, null); 
    TextView tvName = (TextView) v.findViewById(R.id.tvImageName); 
    ImageView img = (ImageView) v.findViewById(R.id.imgView); 

    tvName.setText(listImage.get(position).getName()); 
    Glide.with(context).load(listImage.get(position).getUrl()).into(img); 

    return v; 
} 
}

我的日志：

                [ 08-24 12:12:06.779 12936:12986 D/   ] 

    HostConnection::get() New Host Connection established 0x939ca540, tid 12986 


                   [ 08-24 
    12:12:06.781 12936:12986 W/   ] 
                   Unrecognized GLES 
    max version string in extensions: ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_dma_v1 
    08-24 12:12:06.783 12936-12986/kelseyvanderheijden.vvop6 I/OpenGLRenderer: Initialized EGL, version 1.4 
08-24 12:12:06.783 12936-12986/kelseyvanderheijden.vvop6 D/OpenGLRenderer: Swap behavior 1 
08-24 12:12:06.783 12936-12986/kelseyvanderheijden.vvop6 W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without... 
08-24 12:12:06.783 12936-12986/kelseyvanderheijden.vvop6 D/OpenGLRenderer: Swap behavior 0 
08-24 12:12:06.786 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglCreateContext: 0xa04301e0: maj 2 min 0 rcv 2 
08-24 12:12:06.806 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:06.900 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:06.983 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:07.035 12936-12936/kelseyvanderheijden.vvop6 W/art: Before Android 4.1, method int android.support.v7.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView 
08-24 12:12:07.047 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:07.078 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:07.106 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:07.564 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:11.759 12936-12981/kelseyvanderheijden.vvop6 V/FA: Inactivity, disconnecting from AppMeasurementService 
08-24 12:12:16.570 12936-12964/kelseyvanderheijden.vvop6 W/DynamiteModule: Local module descriptor class for com.google.firebase.auth not found. 
08-24 12:12:35.114 12936-12941/kelseyvanderheijden.vvop6 I/art: Do partial code cache collection, code=30KB, data=30KB 
08-24 12:12:35.114 12936-12941/kelseyvanderheijden.vvop6 I/art: After code cache collection, code=30KB, data=30KB 
08-24 12:12:35.114 12936-12941/kelseyvanderheijden.vvop6 I/art: Increasing code cache capacity to 128KB 
08-24 12:12:37.186 12936-12936/kelseyvanderheijden.vvop6 I/AppCompatViewInflater: app:theme is now deprecated. Please move to using android:theme instead. 
08-24 12:12:37.353 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.367 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.379 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.386 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.395 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.412 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.419 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.428 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.439 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.449 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.452 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.455 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.464 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.467 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.470 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.478 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.482 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.485 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.496 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.501 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.503 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.510 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.515 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.518 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.526 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.529 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.533 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.543 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.548 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.550 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.560 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.565 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.568 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.578 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.584 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.588 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.599 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.604 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.612 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.620 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.624 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.633 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.637 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.646 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.652 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.660 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.666 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.676 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.683 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.692 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.699 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.709 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.713 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.726 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.732 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.743 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.750 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.759 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.763 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.777 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.782 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.792 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.796 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.809 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.815 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.826 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.833 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.842 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.849 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.860 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.864 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.876 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.881 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.894 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.899 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.909 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.920 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.926 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.930 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.943 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.948 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.958 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.963 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.976 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.980 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.993 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:37.999 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.009 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.014 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.027 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.035 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.043 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.047 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.060 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.066 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.076 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.082 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.092 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.100 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.110 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.115 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.127 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.132 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.143 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.147 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.159 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.165 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.176 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.180 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.191 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.198 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.211 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.216 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.227 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.232 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.242 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.249 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.260 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.264 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.277 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.284 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.292 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.299 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.310 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.322 12936-12941/kelseyvanderheijden.vvop6 I/art: Do partial code cache collection, code=61KB, data=61KB 
08-24 12:12:38.326 12936-12941/kelseyvanderheijden.vvop6 I/art: After code cache collection, code=61KB, data=61KB 
08-24 12:12:38.326 12936-12941/kelseyvanderheijden.vvop6 I/art: Increasing code cache capacity to 256KB 
08-24 12:12:38.346 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:38.402 12936-12943/kelseyvanderheijden.vvop6 W/art: Suspending all threads took: 9.810ms 
08-24 12:12:38.417 12936-12986/kelseyvanderheijden.vvop6 D/EGL_emulation: eglMakeCurrent: 0xa04301e0: ver 2 0 (tinfo 0xa213d270) 
08-24 12:12:44.946 12936-12936/kelseyvanderheijden.vvop6 I/AppCompatViewInflater: app:theme is now deprecated. Please move to using android:theme instead.

我在做什么错？提前谢谢了！

来源

2017-08-24 kelseyvdheijden

切换标签页时是否会在Logcat中显示任何可疑内容？ –

谢谢你的回答。我不确定。我已将logcat添加到帖子中。你有什么想法？ – kelseyvdheijden

这些是切换标签页时发生的日志吗？我有兴趣了解当您第二次按下标签时Logcat中打印的内容（并且不显示任何内容）。您似乎正确地从Firebase中读取数据（正如您首次看到它显示的那样），并且我确实认为您的问题是由适配器或标签片段代码引起的 –

将从Firebase中获取数据的代码从onCreateView方法移至onResume()方法。

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

    progressDialog = new ProgressDialog(getActivity()); 
    progressDialog.setMessage("Aan het laden..."); 
    progressDialog.show(); 

    mDatabaseRef = FirebaseDatabase.getInstance().getReference(StandBeker_Fragment_Admin.FB_DATABASE_PATH); 
    mDatabaseRef.addValueEventListener(new ValueEventListener() { 
     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      progressDialog.dismiss(); 

      for(DataSnapshot snapshot : dataSnapshot.getChildren()) { 
       ImageUpload img = snapshot.getValue(ImageUpload.class); 
         imgList.add(img); 
      } 
      adapter = new StandBeker_Adapter(getActivity(), R.layout.fragment_stand_beker, imgList); 
      lv.setAdapter(adapter); 
     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 
     } 
    }); 

}

来源

2017-08-24 12:28:47

谢谢你的回答。我想到了这一点（我只是试了一次），但不幸的是这并没有解决问题。 – kelseyvdheijden

在'onCreateView（）'中添加一个断点并调试应用程序。看看该方法是否被调用。 –

我不认为它被称为。 '08-24 13：27：12.061 1184-1184/kelseyvanderheijden.vvop6 I/AppCompatViewInflater：app：theme现在已被弃用。请改为使用android：主题。 ' – kelseyvdheijden

FireBase实时数据库在第二个视图上为空

回答

相关问题