Question

任何人都可以帮忙解决这个问题吗？

情况是我有一个来自sqlite的数据的recyclerview填充它。当我点击一个项目时，将启动一个新活动，该活动对于之后的每个项目都是唯一的。

但问题是，当我点击来自recyclerview的项目B时，它将始终启动我不想要的项目A活动，并且对于recyclerview中的每个项目都是相同的。

是他们正确的方法吗？

继承我的Recyclerview项目代码点击

 public void onBindViewHolder(reg_ViewHolder holder, final int position) {
    holder.pet_name.setText(items.get(position).getPet_name());
    holder.pet_type.setText(items.get(position).getPet_type());
    holder.pet_breed.setText(items.get(position).getPet_breed());
    holder.btndel.setTag(items.get(position).getPet_name());
    holder.btnpet_guide.setTag(items.get(position));
    holder.btnpet_guide.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            register_pet_database=new Register_pet_database(v.getContext());
            Cursor compare=register_pet_database.getBreed();
            String name = compare.getString(compare.getColumnIndex("Pet_breed"));
            try {
                if (compare.getCount()>0 && compare.moveToFirst()) {
                        do {
                            if (name.equals("Chow Chow")) {
                                    Intent intent = new Intent(data_context, dog_chow_chow.class);
                                    data_context.startActivity(intent);
                                    break;
                            }
                            else if (name.equals("Beagle")) {
                                    Intent intent = new Intent(data_context, dog_beagle.class);
                                    data_context.startActivity(intent);
                                    break;

                            }

                        } while (compare.moveToNext());
                    }
            }catch (Exception e){
                e.printStackTrace();
            }
            compare.close();
        }
    });

我在数据库中获取数据的代码

    public Cursor getBreed()
{
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cur=db.rawQuery("select Pet_breed from "+TABLE_NAME,null);
    return cur;
}

被修改

继承我的新适配器

public class reg_Adapter  extends RecyclerView.Adapter<reg_ViewHolder>{
Context data_context;
Register_pet_database register_pet_database;
 ArrayList<db_getItem> items;
ItemClicklistiener listener;

db_getItem adapter;
DBAdapter dbAdapter;
public reg_Adapter(Context data_context, ArrayList<db_getItem> items) {
    this.data_context= data_context;
    this.items = items;
}

public reg_ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.reg_pet_recycler, parent, false);
    return new reg_ViewHolder(view, data_context, items);
}
public void add(db_getItem pet) {
    items.add(0, pet);
    notifyItemInserted(0);

}
@Override
public void onBindViewHolder(reg_ViewHolder holder, final int position) {
    holder.pet_name.setText(items.get(position).getPet_name());
    holder.pet_type.setText(items.get(position).getPet_type());
    holder.pet_breed.setText(items.get(position).getPet_breed());
    holder.btndel.setTag(items.get(position).getPet_name());
    holder.btnpet_guide.setTag(items.get(position));
    holder.btnpet_guide.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            register_pet_database=new Register_pet_database(v.getContext());
            items=new ArrayList<>();

            Cursor compare=register_pet_database.getBreed();

            try {
                if (compare.getCount() > 0 && compare.moveToFirst()) {
                    do {
                        String name = compare.getString(compare.getColumnIndex("Pet_breed"));
                        String chow="Chow Chow";
                        String beagle="Beagle";
                        if (name.equals(chow)) {
                            listener.onItemClicked(position, dog_chow_chow.class);
                            break;
                        }
                        else if (name.equals(beagle)) {
                            listener.onItemClicked(position, dog_beagle.class);
                            break;
                        }

                    } while (compare.moveToNext());
                }
            }catch (Exception e){
                e.printStackTrace();
            }
            compare.close();
        }
    });
    holder.btndel.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            register_pet_database=new Register_pet_database(v.getContext());
            Integer deleted =register_pet_database.deleteData(v.getTag().toString());
            if (deleted > 0) {
                items.remove(position);
                notifyItemRemoved(position);
                Toast.makeText(v.getContext(), "Pet Has been Remove", Toast.LENGTH_SHORT).show();

            }
            else{
                Toast.makeText(v.getContext(), "Pet not Removed", Toast.LENGTH_SHORT).show();
            }
        }

    });
}

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

}

以下是我的MyFragment代码

public class pet_tab extends Fragment{
    RecyclerView recyclerView;
    Register_pet_database register_pet_database;
    ArrayList<db_getItem> arrayList;
    reg_Adapter reg_adapter;
    db_getItem item;
    Button btndel, btnpet_guide;
    TextView pet_type, pet_breed;
    Cursor c;

    public pet_tab() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_pet_tab, container, false);
        recyclerView = (RecyclerView) view.findViewById(R.id.reg_pet_recycler);
        loadDb();
        return view;
    }

    public void loadDb() {
        register_pet_database = new Register_pet_database(getActivity());
        DBAdapter db = new DBAdapter(getActivity());
        db.openDB();
        arrayList = new ArrayList<>();
        c = register_pet_database.queryData("select * from Pet_Registered");
        final int position = 0;
        try {
            if (c != null) {
                if (c.moveToFirst()) {
                    do {
                        db_getItem item = new db_getItem();
                        item.setPet_name(c.getString(1));
                        item.setPet_type(c.getString(2));
                        item.setPet_breed(c.getString(3));
                        arrayList.add(item);

                    } while (c.moveToNext());
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        reg_Adapter adapter = new reg_Adapter(getActivity(), arrayList);
        recyclerView.setHasFixedSize(true);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setAdapter(adapter);
    }

    ItemClicklistiener listener=new ItemClicklistiener() {
        @Override
        public void onItemClicked(int adapterPosition, Class<?> cls) {
            Intent intent = new Intent(getContext(), cls);
           getContext().startActivity(intent);
        }
    };
}

Answer 1

创建一个名为ItemClickListener的界面，其结构如下：

interface ItemClickListener {
  void onItemClicked(int adapterPosition, Class<?> cls);
}

现在在activity中实现此功能，如下所示：

ItemClickListener listener = new ItemClickListener {
 @Override
 public void onItemClicked(int position, Class<?> cls) {
   Intent intent = new Intent(ActivityName.this, cls);
   ActivityName.startActivity(intent);
 }
};

将listener传递给recyclerview的适配器，并修改适配器的onBindViewHolder，如下所示：

    public void onBindViewHolder(reg_ViewHolder holder, final int position) {
       holder.pet_name.setText(items.get(position).getPet_name());
       holder.pet_type.setText(items.get(position).getPet_type());
       holder.pet_breed.setText(items.get(position).getPet_breed());
       holder.btndel.setTag(items.get(position).getPet_name());
       holder.btnpet_guide.setTag(items.get(position));
       holder.btnpet_guide.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               register_pet_database=new Register_pet_database(v.getContext());
               Cursor compare=register_pet_database.getBreed();
               String name = compare.getString(compare.getColumnIndex("Pet_breed"));
               try {
                   if (compare.getCount()>0 && compare.moveToFirst()) {
                           do {
                               if (name.equals("Chow Chow")) {
                                       listener.onItemClicked(position, dog_chow_chow.class);
                                       break;
                               }
                               else if (name.equals("Beagle")) {
                                       listener.onItemClicked(position, dog_beagle.class);
                                       break;

                               }

                           } while (compare.moveToNext());
                       }
               }catch (Exception e){
                   e.printStackTrace();
               }
               compare.close();
           }
       });

请更改适配器，如下所示，唯一的区别是提供了一个可以从pet_tab片段设置的setter方法：

public class reg_Adapter  extends RecyclerView.Adapter<reg_ViewHolder>  

{
Context data_context;
Register_pet_database register_pet_database;
 ArrayList<db_getItem> items;
ItemClicklistiener listener;

db_getItem adapter;
DBAdapter dbAdapter;
public reg_Adapter(Context data_context, ArrayList<db_getItem> items) {
    this.data_context= data_context;
    this.items = items;
}

public void setItemClickListener(ItemClickListener listener) {
    this.listener = listener;
}

public reg_ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.reg_pet_recycler, parent, false);
    return new reg_ViewHolder(view, data_context, items);
}
public void add(db_getItem pet) {
    items.add(0, pet);
    notifyItemInserted(0);

}

@Override
public void onBindViewHolder(reg_ViewHolder holder, final int position) {
    holder.pet_name.setText(items.get(position).getPet_name());
    holder.pet_type.setText(items.get(position).getPet_type());
    holder.pet_breed.setText(items.get(position).getPet_breed());
    holder.btndel.setTag(items.get(position).getPet_name());
    holder.btnpet_guide.setTag(items.get(position));
    holder.btnpet_guide.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        register_pet_database=new Register_pet_database(v.getContext());
        items=new ArrayList<>();

        Cursor compare=register_pet_database.getBreed();

        try {
            if (compare.getCount() > 0 && compare.moveToFirst()) {
                do {
                    String name = compare.getString(compare.getColumnIndex("Pet_breed"));
                    String chow="Chow Chow";
                    String beagle="Beagle";
                    if (name.equals(chow)) {
                        listener.onItemClicked(position, dog_chow_chow.class);
                        break;
                    }
                    else if (name.equals(beagle)) {
                        listener.onItemClicked(position, dog_beagle.class);
                        break;
                    }

                } while (compare.moveToNext());
            }
        }catch (Exception e){
            e.printStackTrace();
        }
        compare.close();
    }
});
holder.btndel.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        register_pet_database=new Register_pet_database(v.getContext());
        Integer deleted =register_pet_database.deleteData(v.getTag().toString());
        if (deleted > 0) {
            items.remove(position);
            notifyItemRemoved(position);
            Toast.makeText(v.getContext(), "Pet Has been Remove", Toast.LENGTH_SHORT).show();

        }
        else{
            Toast.makeText(v.getContext(), "Pet not Removed", Toast.LENGTH_SHORT).show();
        }
    }

  });
}

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

如何在recyclerview中获取项目的位置并获取sqlite数据库数据进行比较

1 个答案: