Comment conserver RecyclerView après une rotation Android?

Question

Lorsque je fais pivoter mon périphérique, mon instance d'activité est détruite, ce qui démarre un nouveau onCreate. Je ne peux pas comprendre comment repeupler mon RecyclerView après l'orientation de l'écran. J'ai essayé quelques solutions impliquant AndroidManifest: android:configChanges="keyboardHidden|orientation" et aussi avec onSaveInstanceState, but could not get it to work. I have added onSaveInstanceState and onRestoreInstanceState` le code de base à ma question, qui ne fait rien pour le moment.

Merci

MainActivity.java

public class MainActivity extends AppCompatActivity implements RepositoryAdapter.OnItemClickListener { 

    private static final String LOG_TAG = "MainActivity"; 

    @BindView(R.id.fab_search_github_user) 
    FloatingActionButton fabSearchGitHubUser; 

    @BindView(R.id.et_search_user) 
    EditText etSearchUser; 

    @BindView(R.id.btn_search_user) 
    Button btnSearchUser; 

    @BindView(R.id.github_user) 
    TextView tvOwner; 

    @BindView(R.id.github_repository_recyclerview) 
    RecyclerView mRecyclerView; 

    private RepositoryAdapter mAdapter; 

    private Api mApi; 

    private Owner mOwner; 

    boolean isSearchToggled = false; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 
     ButterKnife.bind(this); 

     mApi = ApiUtils.getApi(); 

     // RecyclerView 
     RecyclerView.LayoutManager linearLayoutManager = new LinearLayoutManager(getApplicationContext()); 
     mRecyclerView.setLayoutManager(linearLayoutManager); 
     mRecyclerView.setHasFixedSize(true); 

     // Floating action button to toggle user search field. 
     FloatingActionButton floatingActionButton = (FloatingActionButton) findViewById(R.id.fab_search_github_user); 
     floatingActionButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       toggleSearch(); 
      } 
     }); 
    } 

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

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

    @OnClick(R.id.btn_search_user) 
    public void onSearchBtnClicked(View view) { 
     if (!TextUtils.isEmpty(etSearchUser.getText())) { 
      String searchedUser = etSearchUser.getText().toString(); 

      // Search will be done offline when no internet, otherwise online. 
      if (!isNetworkAvailable()) { 
       Toast.makeText(this, "No internet, searching offline", Toast.LENGTH_SHORT).show(); 
       mOwner = Owner.getByUsername(searchedUser); 
       if (mOwner != null) { 
        searchByUsername(searchedUser); 
        tvOwner.setText(searchedUser); 
       } else { 
        if (mAdapter != null) { 
         mAdapter.clearRecyclerView(); 
        } 
        tvOwner.setText(getString(R.string.user_not_found, searchedUser)); 
       } 
      } else { 
       loadRepository(searchedUser); 
       tvOwner.setText(searchedUser); 
       Toast.makeText(this, "Searching online", Toast.LENGTH_SHORT).show(); 
      } 
     } else { 
      Log.i(LOG_TAG, "Search field is empty"); 
     } 

     if (view != null) { 
      InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE); 
      imm.hideSoftInputFromWindow(view.getWindowToken(), 0); 
     } 

     toggleSearch(); 
    } 

    /** 
    * Search local user by username. 
    * 
    * @param username The local user that is searched for. 
    */ 
    public void searchByUsername(String username) { 
     mAdapter = new RepositoryAdapter(Repository.getList(username), MainActivity.this); 
     mRecyclerView.setAdapter(mAdapter); 
    } 

    /** 
    * Search online on GitHub to retrieve all user repositories. 
    * 
    * @param username The GitHub user that is searched for. 
    */ 
    public void loadRepository(String username) { 
     mApi.listRepository(username).enqueue(new Callback<List<Repository>>() { 
      @Override 
      public void onResponse(Call<List<Repository>> call, Response<List<Repository>> response) { 
       mAdapter = new RepositoryAdapter(response.body(), MainActivity.this); 
       mRecyclerView.setAdapter(mAdapter); 
      } 

      @Override 
      public void onFailure(Call<List<Repository>> call, Throwable t) { 
       Log.e("MainActivity", "error loading from API"); 
      } 
     }); 
    } 

    @Override 
    public void onItemClick(Repository repository) { 
     if (isNetworkAvailable()) { 
      mOwner = Owner.getByUsername(repository.owner.getLogin()); 
      Repository mRepository = Repository.getByRepositoryName(repository.getName()); 

      if (mOwner != null) { 
       if (mRepository != null) { 
        // Repository is already in Database. 
       } else { 
        // Selected repository is added to Database 
        mRepository = new Repository(mOwner); 
        mRepository.setName(repository.getName()); 
        mRepository.setLogin(repository.owner.getLogin()); 
        mRepository.setDescription(repository.getDescription()); 
        mRepository.setStargazersCount(repository.getStargazersCount()); 
        mRepository.setForksCount(repository.getForksCount()); 
        mRepository.save(); 
       } 
      } else { 
       // selected repository and its owner are added to Database 
       mOwner = new Owner(); 
       mOwner.setLogin(repository.owner.getLogin()); 
       mOwner.setAvatarUrl(repository.owner.getAvatarUrl()); 
       mOwner.setReposUrl(repository.owner.getReposUrl()); 
       mOwner.save(); 

       mRepository = new Repository(mOwner); 
       mRepository.setName(repository.getName()); 
       mRepository.setLogin(repository.owner.getLogin()); 
       mRepository.setDescription(repository.getDescription()); 
       mRepository.setStargazersCount(repository.getStargazersCount()); 
       mRepository.setForksCount(repository.getForksCount()); 
       mRepository.save(); 
      } 
     } 

     // Send intent with repository name to repository detail activity. 
     Intent intent = new Intent(MainActivity.this, RepositoryDetailActivity.class); 
     intent.putExtra(INTENT_KEY_REPOSITORY, repository.getName()); 
     startActivity(intent); 
    } 

    /** 
    * Toggle search field according to its state. 
    */ 
    private void toggleSearch() { 
     if (!isSearchToggled) { 
      etSearchUser.setVisibility(View.VISIBLE); 
      btnSearchUser.setVisibility(View.VISIBLE); 
      isSearchToggled = true; 
     } else { 
      etSearchUser.setVisibility(View.GONE); 
      btnSearchUser.setVisibility(View.GONE); 
      isSearchToggled = false; 
     } 
    } 

    /** 
    * Checks if network is available on the device. 
    * 
    * @return Return when networkInfo is not null and networkInfo is connected. 
    */ 
    private boolean isNetworkAvailable() { 
     ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); 
     NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo(); 
     return networkInfo != null && networkInfo.isConnected(); 
    } 
} 

Answer 1

1. configChanges devraient également inclure ScreenSize si vous voulez désactiver recréer la classe d'activité. Version si correcte:

   android: configChanges = « keyboardHidden | orientation | ScreenSize »

2. Pour enregistrer le contenu de vue recycleur sans désactiver vous recréer devez stocker le contenu dans un endroit qui n'est pas lié au cycle de vie de l'activité ou passez-le à bundle dans onSaveInstanceState et récupérez-le plus tard dans onRestoreInstanceState ou dans onCreate. S'il vous plaît, jetez un oeil à https://developer.android.com/guide/components/activities/activity-lifecycle.html