android-fragments

问题 I have project with navigation drawer with fragment, with 5 menu, the problem is when i go to menu 4 and the i press the back button the app closed, but i need the app back to first menu which is all the menu in fragment. This is code for Main Activity (Navigation Drawer) public class MainActivity extends AppCompatActivity{ DrawerLayout mDrawerLayout; NavigationView mNavigationView; FragmentManager mFragmentManager; FragmentTransaction mFragmentTransaction; @Override protected void onCreate

问题 Initial Question (18/05/2020): So with the latest Update from androidx.fragment:fragment:1.3.0- alpha07 to androidx.fragment:fragment:1.3.0- alpha08 I get the error: FragmentXY is attempting to registerForActivityResult after being created. Fragments must call registerForActivityResult() before they are created (i.e. initialization, onAttach(), or onCreate()). I used to check permissions in my StartFragment (Single Activity App, in onViewCreated) after showing to the User information about

问题 Initial Question (18/05/2020): So with the latest Update from androidx.fragment:fragment:1.3.0- alpha07 to androidx.fragment:fragment:1.3.0- alpha08 I get the error: FragmentXY is attempting to registerForActivityResult after being created. Fragments must call registerForActivityResult() before they are created (i.e. initialization, onAttach(), or onCreate()). I used to check permissions in my StartFragment (Single Activity App, in onViewCreated) after showing to the User information about

问题 In my app I use NavController with Fragments. In some fragments I need to access views on MainActivity layout. I do that in this way: val fab: FloatingActionButton = requireActivity().findViewById(R.id.fab) This works properly as expected. However, one view does not want to be called and the findViewById() returns null. The layout structure is like this. In activity_main.xml <androidx.drawerlayout.widget.DrawerLayout <androidx.coordinatorlayout.widget.CoordinatorLayout ....> <FrameLayout

问题 I am making a calculator app and want to update history in second fragment but not able to find a perfect solution for updating ListView in second fragment. I tried many solutions but none of them worked properly. I'm using ViewPager to swipe between calculator and history fragments . I tired bundle class but if I use bundle in OnCreat method of first Fragment(CalculatorFragment) with ViewPager it shows me blank screen after starting an App & if I use Bundle class in Equal Button it crashes

问题 I have this line in my code: linearLayout.setBackground(drawable); setBackground() shows the following error: Call requires API level 16 (current min is 14) What does this mean? Can I raise my API level? What does a higher/lower API level mean? Does it limit the amount of devices my app can be used on if the API level is higher? 回答1: What does this mean? It means that the setBackground(Drawable) method was added in API Level 16, and older devices do not have it. However, your app's

问题 Could any one help me out with this situation. I have implemented OnUserInteraction() method for Android Activity it is working fine for me. But I want it for Fragments too.How can i able call OnUserInteraction() or is there any another way to identify userInteraction with the UI . 回答1: @Sunil's answer causes java.lang.StackOverflowError so I corrected it. Below code works smoothly Create a java class in your app named UserInterationListener and put below code there public interface

问题 there is default constructor in fragment, i want to know that what it's use and what functionality it provides? and i run the code without it it worked perfectly and i can't find any error in removing it public class SongListFragment extends Fragment { private static final String SONG_IDS = "song_ids"; // TODO: Rename and change types of parameters private int[] songIds; private OnFragmentInteractionListener mListener; public SongListFragment() { // Required empty public constructor } // TODO

问题 In my custom view I have a Java class running a simple game. When the game is finished I'd like to display my DialogFragment , but the getFragmentManager() method seems to be undefined. FragmentManager manager = getFragmentManager(); Finish finish = new Finish(); finish.show(manager, "done"); I've tried getting the manager through a Fragment obj as: Fragment fragment = new Fragment(); FragmentManager manager = fragment.getFragmentManager(); But that returns as null. I know it's a new Fragment

问题 I am trying to instantiate one ViewModel to use across all of my Activity(s). public class LaunchActivity extends Activity { private Controller control; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_launch); control = ViewModelProviders.of(this).get(Controller.class); } } but I got an error at control = ViewModelProviders.of(this) <-- stating that it cannot resolve of(this) , but based on the example here by