RecyclerViewをAndroidの回転の後に保持するにはどうしたらいいですか？

Question

デバイスを回転させると、新しいonCreateを開始するアクティビティインスタンスが破棄されます。画面の向きを変えてRecyclerViewを再作成する方法がわかりません。私はいくつかの解決策AndroidManifestを含意しました：android:configChanges="keyboardHidden|orientation"とonSaveInstanceState, but could not get it to work. I have added onSaveInstanceState and onRestoreInstanceState`ベースコードを私の質問に、現時点では何もしません。

おかげ

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. アクティビティクラスを再オフにしたい場合はconfigChangesも画面サイズを含める必要があります。だから、正しいバージョン：

   アンドロイド：configChangesは=「keyboardHidden |オリエンテーション|画面サイズ」

2. 再作成無効にすることなくリサイクルビューのコンテンツを保存するためにあなたが活動のライフサイクルにバインドされていないいくつかの場所にコンテンツを保存するために持っていますか、それをonSaveInstanceStateにバンドルして、後でonRestoreInstanceStateまたはonCreateに渡します。してください、見てくださいhttps://developer.android.com/guide/components/activities/activity-lifecycle.html