如何在主要活动中使用按钮onclicklistener作为回收浏览项目

Question

我在Android应用程序工作时面临此问题：我有一个recycleview，每个项目都有一个删除按钮。我知道我可以在适配器中onBindViewHolder内的每个行项目中添加按钮onclicklistener，但是我希望它专门用于从主动脉内部而不是适配器使用。这是我的 recycleView 的简短草图：

草图

这是我适配器的代码：

public class EntryAdapter extends RecyclerView.Adapter<EntryAdapter.MyViewHolder> {
    private Context context;
    private CRUD db;
    private List<Entry> entryList;
    public class MyViewHolder extends RecyclerView.ViewHolder {
        ImageView type;
        ImageView person;
        TextView amount;
        TextView amount_ron;
        ImageButton deleteB, editB, payB;
        TextView description;
        TextView timestamp;
        TextView positionTxt, noHolderPositionTxt;
        LinearLayout containter;
        Typeface SR, SB, SL;
        MyViewHolder(View view) {
            super(view);
            this.SB = Typeface.createFromAsset(context.getAssets(), "fonts/sansation_bold.ttf");
            this.SR = Typeface.createFromAsset(context.getAssets(), "fonts/sansation_regular.ttf");
            this.SL = Typeface.createFromAsset(context.getAssets(), "fonts/sansation_light.ttf");
            containter = view.findViewById(R.id.item_container);
            type = view.findViewById(R.id.debt_type);
            person = view.findViewById(R.id.debt_person);
            amount = view.findViewById(R.id.entry_cost);
            amount.setTypeface(SR);
            amount_ron = view.findViewById(R.id.entry_cost_ron);
            amount_ron.setTypeface(SR);
            deleteB = view.findViewById(R.id.delete_button);
            editB = view.findViewById(R.id.edit_button);
            payB = view.findViewById(R.id.pay_button);
            description = view.findViewById(R.id.descriptionTxt);
            description.setTypeface(SL);
            timestamp = view.findViewById(R.id.timestamp);
            timestamp.setTypeface(SR);
            positionTxt = view.findViewById(R.id.position);
            noHolderPositionTxt = view.findViewById(R.id.positionnotwithholder);
            db = new CRUD(context);
        }
    }
    public EntryAdapter(Context context, List<Entry> entryList) {
        this.context = context;
        this.entryList = entryList;
    }
    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_entry, parent, false);
        return new MyViewHolder(itemView);
    }
    @Override
    public void onBindViewHolder(@NonNull final MyViewHolder holder, final int position) {
        Entry entry = entryList.get(holder.getAdapterPosition());
        holder.positionTxt.setText(String.valueOf(holder.getAdapterPosition()));
        holder.noHolderPositionTxt.setText(String.valueOf(position));
        switch(entry.getType()){
            case "FOOD": holder.type.setImageResource(R.drawable.food);
                break;
            case "FLOWERS": holder.type.setImageResource(R.drawable.flowers);
                break;
            case "GROCERIES": holder.type.setImageResource(R.drawable.groceries);
                break;
            case "HOLIDAY": holder.type.setImageResource(R.drawable.holiday);
                break;
            case "PHARMACY": holder.type.setImageResource(R.drawable.pharmacy);
                break;
            case "BILLS": holder.type.setImageResource(R.drawable.bills);
                break;
            case "CLOTHES": holder.type.setImageResource(R.drawable.clothes);
                break;
            case "TRANSPORT": holder.type.setImageResource(R.drawable.transport);
                break;
            case "ITEMS": holder.type.setImageResource(R.drawable.items);
                break;
            case "OTHERS": holder.type.setImageResource(R.drawable.others);
                break;
        }
        switch (entry.getPerson()){
            case "ew": holder.person.setImageResource(R.drawable.crisu_to_radu_small);
                break;
            case "wr": holder.person.setImageResource(R.drawable.radu_to_crisu_big);
                break;
        }
        switch (entry.getIsPaid()){
            case "YES": holder.containter.setAlpha((float) 0.3);
                        holder.payB.setVisibility(View.GONE);
                        holder.deleteB.setVisibility(View.GONE);
                        holder.editB.setVisibility(View.GONE);
                break;
            case "NO":  holder.containter.setAlpha((float) 1);
                        holder.payB.setVisibility(View.VISIBLE);
                        holder.deleteB.setVisibility(View.VISIBLE);
                        holder.editB.setVisibility(View.VISIBLE);
                break;
        }
        holder.amount.setText(entry.getAmount());
        holder.description.setText(entry.getDescription());
        holder.timestamp.setText(formatDate(entry.getTimestamp()));
//                deleteEntry(holder.getAdapterPosition());
    }
    @Override
    public int getItemCount() {
        return entryList.size();
    }
    private void deleteEntry(int position) {
        db.deleteEntry(entryList.get(position));
        entryList.remove(position);
        notifyItemRemoved(position);
        notifyDataSetChanged();
        notifyItemRangeChanged(position, entryList.size());
    }
    private String formatDate(String dateStr) {
        try {
            @SuppressLint("SimpleDateFormat") SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            Date date = fmt.parse(dateStr);
            @SuppressLint("SimpleDateFormat") SimpleDateFormat fmtOut = new SimpleDateFormat("MMM d, HH:mm");
            return fmtOut.format(date);
        } catch (ParseException ignored) {}
        return "";
    }
}

这是我的主要目的：

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        fonts();

        recyclerView = findViewById(R.id.recycler_view);
        no_entry_message = findViewById(R.id.no_entry_message);
        no_entry_message.setTypeface(SL);
        title = findViewById(R.id.finance_title);
        title.setTypeface(SB);
        subtitle = findViewById(R.id.finance_subtitle);
        subtitle.setTypeface(SL);
        card_title = findViewById(R.id.total_title);
        card_title.setTypeface(SR);
        money_amount = findViewById(R.id.total_money);
        money_amount.setTypeface(SB);
        money_rom = findViewById(R.id.total_ron);
        money_rom.setTypeface(SB);
        total_calculation = findViewById(R.id.total_button);
        total_calculation.setTypeface(SR);
        total_container = findViewById(R.id.total_card_container);
        db = new CRUD(this);
        entryList.addAll(db.getAllEntries());
        fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                isUpdateDilog = false;
                addEntryDialog(null, -1);
            }
        });
        mAdapter = new EntryAdapter(this, entryList);
        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);
        emptyList();
    }
//    private void deleteEntry(int position) {
//
//        db.deleteEntry(entryList.get(position));
//        entryList.remove(position);
//        mAdapter.notifyItemRemoved(position);
//        emptyList();
//    }

基本上，每次我单击RecyClerview项目中的删除按钮时，我都希望在MainActivity中发生OnClick事件，并使用方法DeleteEntry（位置），以便我可以从本地SQLITE数据库中删除特定项目。

另外，如果我想从适配器中放入onbindviewholder的条件，例如，我该如何更改（例如）从MainActivity那里进行文本视图的颜色？

更新 - 使用H.Sanati的答案

再次感谢您的答案，H.Sanati。这是我更改的所有内容：

创建此接口：

public interface OnClickListener {
    void onClick(int position, String button_pressed);
}

整数位置将我的项目位置存储在列表中，字符串将告诉我的3个按钮中的哪个。

然后在我的内部> recyclview适配器：

@Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_entry, parent, false);
        final MyViewHolder holder = new MyViewHolder(itemView);
        holder.deleteB.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ((MainActivity)context).onClick(holder.getAdapterPosition(), "DELETE_B");
            }
        });
        holder.editB.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ((MainActivity)context).onClick(holder.getAdapterPosition(), "EDIT_B");
            }
        });
        holder.payB.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ((MainActivity)context).onClick(holder.getAdapterPosition(), "PAY_B");
            }
        });
        return holder;
    }

请注意，DELETEB，EDITB和PAYB都是每个列表项目中出现的所有按钮。上面的界面中的字符串告诉其中哪一个被按下。

然后在我的 mainActivity 中：

public class MainActivity extends AppCompatActivity implements OnClickListener {
@Override
    public void onClick(int item_position, String which_button_was_pressed) {
        switch (which_button_was_pressed)
        {
            case "DELETE_B":
                deleteEntry(item_position);
                Toast.makeText(this, "Delete button at position:" + item_position + "was pressed", Toast.LENGTH_SHORT).show();
                    break;
            case "EDIT_B":
                Toast.makeText(this, "Edit button at position:" + item_position + "was pressed", Toast.LENGTH_SHORT).show();
                break;
            case "PAY_B":
                Toast.makeText(this, "Pay button at position:" + item_position + "was pressed", Toast.LENGTH_SHORT).show();
                break;
        }
    }

这里有一个烤面包按摩，可以确认正确的按钮已按下，然后遵循，我将为每种情况添加我的方法。另外，我建议您在MainAttivity中的方法内（例如，删除方法，可以查看它的滚珠），您应该添加以@@@标记的以下行，以获得准确的列表大小和位置更新：

 private void deleteEntry(int position) {
            db.deleteEntry(entryList.get(position));
            entryList.remove(position);
      @@@   mAdapter.notifyItemRemoved(position);
      @@@   mAdapter.notifyDataSetChanged();
      @@@   mAdapter.notifyItemRangeChanged(position, entryList.size());
            emptyList();
        }

希望这会有所帮助。谢谢！

Answer 1

首先，创建一个接口：

public interface OnClickListener {
    void onClick();
}

然后在您的活动中实现此接口：

class MainActivity extends AppCompatActivity implements OnClickListener {
    @Override
    public void onClick() {
        //code
    }
}

在您的recyclerview中调用它之后，请在OnClick方法中做任何您想做的事情：

((MainActivity)context).onClick();

最好在onCreateViewHolder中设置侦听器，以便在recyclerview中平滑滚动：

 @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_entry, parent, false);
        MyViewHolder holder = new MyViewHolder(view);
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ((MainActivity)context).onClick();
            }
        });
        return holder;
    }