削除RecyclerViewから項目およびレルムDB

Question

Image

私はこのRecyclerViewにしてRealm DBに項目を追加しEditTextを持っています。それはうまく動作します。問題は、RecyclerViewとRealm DBの両方からこれらのアイテムを削除する方法がわかりません。フラグメントまたはアダプターでこれを行う必要がありますか？そしてどうやって？ありがとう！

上部に画像があり、アプリのスクリーンショットが表示されています。

ここ

がRecyclerViewがあるFragment次のとおりです、

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    xmlns:design="http://schemas.android.com/apk/res-auto" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:orientation="horizontal" 
    tools:context="com.segunfamisa.sample.bottomnav.MainActivity"> 

    <ImageButton 
     android:id="@+id/delete" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:tint="#03A9F4" 
     android:scaleType="centerInside" 
     android:background="#ffffff" 
     android:layout_alignParentLeft="true" 
     android:layout_centerVertical="true" 
     android:onClick="deleteItem"/> 

    <TextView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:id="@+id/textViewItemNameTD" 
     android:textSize="14dp" 
     android:textColor="#212121" 
     android:background="#ffffff" 
     android:padding="10dp" 
     android:layout_toRightOf="@+id/delete"/> 

    <ImageButton 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:src="@drawable/arrow" 
     android:scaleType="centerInside" 
     android:background="#ffffff" 
     android:layout_alignParentRight="true" 
     android:layout_centerVertical="true"/> 

</RelativeLayout> 

Answer 1

ただ、直接RealmResultsでRealmRecyclerViewAdapterを使用します。

public class FragmentMyList extends Fragment{ 

    private RecyclerView recyclerView; 
    private EditText editTxt; 
    private FloatingActionButton btn; 
    private Item item; 
    private ArrayList<Item> itemList; 
    private AdapterItemsRecycler adapterItemsRecycler; 
    private Realm realm; 
    RealmResults<Item> results; 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     View vistaADevolver = inflater.inflate(R.layout.fragment_my_list, container, false); 
     getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN); 

     Realm.init(getContext()); 
     realm = Realm.getDefaultInstance(); 

     editTxt = (EditText)vistaADevolver.findViewById(R.id.editText); 
     btn = (FloatingActionButton) vistaADevolver.findViewById(R.id.button); 
     recyclerView = (RecyclerView) vistaADevolver.findViewById(R.id.recyclerViewToDo); 

     itemList = new ArrayList<>(); 
     results = realm.where(Item.class).equalTo("id", 1).findAll(); 
     final InputMethodManager inputManager = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE); 

     adapterItemsRecycler = new AdapterItemsRecycler(results, getActivity(), new ItemsListener()); 
     recyclerView.setHasFixedSize(true); 
     recyclerView.addItemDecoration(new SimpleItemDivider(getActivity())); 
     recyclerView.setLayoutManager(new LinearLayoutManager(getActivity(),LinearLayoutManager.VERTICAL, false)); 
     recyclerView.setAdapter(adapterItemsRecycler); 


     btn.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       String itemName = editTxt.getText().toString(); 
       saveIntoDatabase(itemName); 

       inputManager.hideSoftInputFromWindow(getView().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS); 
       editTxt.getText().clear(); 
       adapterItemsRecycler.notifyDataSetChanged(); 
      } 
     }); 
     return vistaADevolver; 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     realm.close(); 
    } 

    private void saveIntoDatabase(final String itemName) { 

     realm.executeTransactionAsync(new Realm.Transaction() { 
      @Override 
      public void execute(Realm bgRealm) { 
       item = bgRealm.createObject(Item.class); 
       item.setName(itemName); 
       item.setPoint(itemName); 
       item.setId(1); 
       Fragment fragment = new Fragment(); 
       Bundle bundle = new Bundle(); 
       bundle.putString("POINT", item.getPoint()); 
       fragment.setArguments(bundle); 
       itemList.add(item); 

      } 
     }, new Realm.Transaction.OnSuccess() { 
      @Override 
      public void onSuccess() { 
       // Transaction was a success. 
       Log.v("database", "Stored ok"); 
      } 
     }, new Realm.Transaction.OnError() { 
      @Override 
      public void onError(Throwable error) { 
       // Transaction failed and was automatically canceled. 
       Log.e("database", error.getMessage()); 
      } 
     }); 

    } 
    class ItemsListener implements AdapterView.OnClickListener{ 

     @Override 
     public void onClick(View view) { 

      Item itemTouched = results.get(recyclerView.getChildAdapterPosition(view)); 
      EscuchadorInterface unEscuchador = (EscuchadorInterface)getActivity(); 
      unEscuchador.itemSelected(itemTouched); 

     } 
    } 
    public interface EscuchadorInterface{ 
     public void itemSelected(Item anItem); 
    } 
} 

マイRecyclerViewアダプタ：

public class AdapterItemsRecycler extends RecyclerView.Adapter { 

    private RealmResults<Item> itemList; 
    private Context context; 
    private View.OnClickListener listener; 
    private Realm realm; 


    public AdapterItemsRecycler(RealmResults<Item> itemList, Context context, View.OnClickListener listener) { 
     this.itemList = itemList; 
     this.context = context; 
     this.listener = listener; 
    } 

    @Override 
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, final int viewType) { 
     LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE); 
     View view = inflater.inflate(R.layout.my_list_detail, parent, false); 
     view.setOnClickListener(listener); 

     ItemViewHolder itemViewHolder = new ItemViewHolder(view); 

     return itemViewHolder; 
    } 

    @Override 
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { 

     Item item = itemList.get(position); 
     ItemViewHolder itemViewHolder = (ItemViewHolder) holder; 
     itemViewHolder.loadItem(item); 

    } 

    @Override 
    public int getItemCount() { 
     return itemList.size(); 
    } 

    private class ItemViewHolder extends RecyclerView.ViewHolder{ 

     private TextView itemText; 
     private ImageButton imageButton; 

     public ItemViewHolder(View view) { 
      super(view); 
      itemText = (TextView) view.findViewById(R.id.textViewItemNameTD); 
      imageButton = (ImageButton) view.findViewById(R.id.delete); 
     } 

     public void loadItem(Item item) { 

      itemText.setText(item.getName()); 
      imageButton.setImageResource(R.drawable.trash); 

     } 

     public ImageButton getImageButton() { 
      return imageButton; 
     } 
    } 
} 

RecyclerViewの詳細ハンドルデータベースとリストとアダプタ間の同期を自動的に行います。

public class FragmentMyList 
     extends Fragment { 
    private RecyclerView recyclerView; 
    private EditText editTxt; 
    private FloatingActionButton btn; 

    private AdapterItemsRecycler adapterItemsRecycler; 

    private Realm realm; 

    RealmResults<Item> results; 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     View vistaADevolver = inflater.inflate(R.layout.fragment_my_list, container, false); 
     getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN); 

     Realm.init(getContext()); 
     realm = Realm.getDefaultInstance(); 

     editTxt = (EditText) vistaADevolver.findViewById(R.id.editText); 
     btn = (FloatingActionButton) vistaADevolver.findViewById(R.id.button); 
     recyclerView = (RecyclerView) vistaADevolver.findViewById(R.id.recyclerViewToDo); 

     results = realm.where(Item.class).equalTo("id", 1).findAll(); 
     final InputMethodManager inputManager = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE); 

     adapterItemsRecycler = new AdapterItemsRecycler(results, new ItemsListener()); 
     recyclerView.setHasFixedSize(true); 
     recyclerView.addItemDecoration(new SimpleItemDivider(getActivity())); 
     recyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false)); 
     recyclerView.setAdapter(adapterItemsRecycler); 

     btn.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       String itemName = editTxt.getText().toString(); 
       saveIntoDatabase(itemName); 

       inputManager.hideSoftInputFromWindow(getView().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS); 
       editTxt.getText().clear(); 
      } 
     }); 
     return vistaADevolver; 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     realm.close(); 
    } 

    private void saveIntoDatabase(final String itemName) { 
     realm.executeTransactionAsync(new Realm.Transaction() { 
      @Override 
      public void execute(Realm bgRealm) { 
       Item item = bgRealm.createObject(Item.class); 
       item.setName(itemName); 
       item.setPoint(itemName); 
       item.setId(1); 
      } 
     }, new Realm.Transaction.OnSuccess() { 
      @Override 
      public void onSuccess() { 
       // Transaction was a success. 
       Log.v("database", "Stored ok"); 
      } 
     }, new Realm.Transaction.OnError() { 
      @Override 
      public void onError(Throwable error) { 
       // Transaction failed and was automatically canceled. 
       Log.e("database", error.getMessage()); 
      } 
     }); 

    } 

    class ItemsListener 
      implements AdapterView.OnClickListener { 
     @Override 
     public void onClick(View view) { 
      Item itemTouched = results.get(recyclerView.getChildAdapterPosition(view)); 
      EscuchadorInterface unEscuchador = (EscuchadorInterface) getActivity(); 
      unEscuchador.itemSelected(itemTouched); 
     } 
    } 

    public interface EscuchadorInterface { 
     public void itemSelected(Item anItem); 
    } 
} 

---

// compile 'io.realm:android-adapters:2.0.0' 
public class AdapterItemsRecycler 
     extends RealmRecyclerViewAdapter<Item, ItemViewHolder> { 
    private View.OnClickListener listener; 

    public AdapterItemsRecycler(OrderedRealmCollection<Item> itemList, View.OnClickListener listener) { 
     super(itemList, true); 
     this.listener = listener; 
    } 

    @Override 
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, final int viewType) { 
     LayoutInflater inflater = LayoutInflater.from(parent.getContext()); 
     View view = inflater.inflate(R.layout.my_list_detail, parent, false); 
     view.setOnClickListener(listener); 
     ItemViewHolder itemViewHolder = new ItemViewHolder(view); 
     return itemViewHolder; 
    } 

    @Override 
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { 
     Item item = getData().get(position); 
     ItemViewHolder itemViewHolder = (ItemViewHolder) holder; 
     itemViewHolder.loadItem(item); 
    } 

    private static class ItemViewHolder 
      extends RecyclerView.ViewHolder { 
     private TextView itemText; 
     private ImageButton imageButton; 

     public ItemViewHolder(View view) { 
      super(view); 
      itemText = (TextView) view.findViewById(R.id.textViewItemNameTD); 
      imageButton = (ImageButton) view.findViewById(R.id.delete); 
     } 

     public void loadItem(Item item) { 
      itemText.setText(item.getName()); 
      imageButton.setImageResource(R.drawable.trash); 
     } 

     public ImageButton getImageButton() { 
      return imageButton; 
     } 
    } 
} 

---

private void deleteFromDatabase(final String itemName) { 
    realm.executeTransactionAsync(new Realm.Transaction() { 
     @Override 
     public void execute(Realm bgRealm) { 
      Item item = bgRealm.where(Item.class).equalTo("name", itemName).findFirst(); 
      if(item != null) { 
       item.deleteFromRealm(); 
      } 
     } 
    }, new Realm.Transaction.OnSuccess() { 
     @Override 
     public void onSuccess() { 
      // Transaction was a success. 
      Log.v("database", "Delete ok"); 
     } 
    }, new Realm.Transaction.OnError() { 
     @Override 
     public void onError(Throwable error) { 
      // Transaction failed and was automatically canceled. 
      Log.e("database", error.getMessage()); 
     } 
    }); 

}