Question

试图让我的测试应用程序我遇到了一个奇怪的问题。我设置onClick以显示AlertDialog和onLongClick以显示ContextMenu。保持触摸一定时间触发两种方法，AlertDialog覆盖ContextMenu。 onClick和onLongClick似乎是并行触发的

我的recycleView

recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getApplicationContext(),
        recyclerView, new RecyclerTouchListener.ClickListener() {
    @Override
    public void onClick(View view, final int position) {
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        ViewGroup viewGroupRecycle = findViewById(R.id.layoutParent);
        View viewUpdate = getLayoutInflater().inflate(R.layout.create, viewGroupRecycle);

        final EditText text = viewUpdate.findViewById(R.id.edit_text);

        builder.setView(viewUpdate);

        builder.setTitle(note_update);

        final int id = notesList.get(position).getId();
        String textStr = notesList.get(position).getText();

        text.setText(textStr);

        text.postDelayed(new Runnable() {
            @Override
            public void run() {
                InputMethodManager keyboard = (InputMethodManager) MainActivity.this
                        .getSystemService(Context.INPUT_METHOD_SERVICE);
                assert keyboard != null;
                keyboard.showSoftInput(text, 0);
            }
        }, 50);

        builder.setPositiveButton(save, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        });

        builder.setNegativeButton(cancel, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });

        final AlertDialog alertDialog = builder.create();
        alertDialog.show();

        alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String strText = removeSeparator(text);
                Boolean check = checked(strText);

                if (check){
                    updatable(strText, id);
                    prepareData();
                    alertDialog.dismiss();
                } else
                    message(error);
            }
        });
    }

    @Override
    public void onLongClick(View view, int position) {

    }
}));

我的ContextMenu

@Override
public void onCreateContextMenu(ContextMenu menu, final View v, ContextMenuInfo menuInfo) {
    menu.add(0, R.id.move, 0, R.string.move_widget);
}

@Override
public boolean onContextItemSelected(MenuItem item) {
try {
    int position = ((NotesAdapter)recyclerView.getAdapter()).getPosition();

    switch (item.getItemId()){
        case R.id.move:
            Intent intent = new Intent(MainActivity.this, WriteNotes.class);
            intent.putExtra("key", position);
            sendBroadcast(intent);
            break;
    }
} catch (Exception e){
    Log.e("TAG", e.getMessage());
}
return super.onContextItemSelected(item);

}

Answer 1

您可以在自定义适配器实现中添加侦听器。它将类似于：

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {

    CustomItemClickListener  customItemClickListener;

    public interface CustomItemClickListener  {
        public void onItemClicked(int position);
        public boolean onItemLongClicked(int position);
    }


    public static class ViewHolder extends RecyclerView.ViewHolder {
        public View v;

        public ViewHolder(View v) {
            super(v);
            this.v = v;
        }
    }

    public RecyclerViewAdapter(CustomItemClickListener  _customItemClickListener;) {
        customItemClickListener = _customItemClickListener;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        holder.v.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                customItemClickListener.onItemClicked(position);
            }
        });
        holder.v.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                customItemClickListener.onItemLongClicked(position);
                return true;
            }
        });
    }

}

活动类如下：

RecyclerView recyclerView;
        ItemsListAdapter adapter;

        recyclerView = (RecyclerView)findViewById(R.id.items_list);
        recyclerView.setHasFixedSize(true);
        LinearLayoutManager   mLinearLayoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(mLinearLayoutManager);
        adapter = new ItemsListAdapter( new CustomItemClickListener() {
            @Override
            public void onItemClick(View v, int position) {
                Log.d(TAG, "onItemClick position:" + position);
                // do what ever you want to do with it
            }
            @Override
            public void onLongClick(View v, int position) {
                Log.d(TAG, "onLongClick position:" + position);
                // do what ever you want to do with it
            }
        });
        recyclerView.setAdapter(adapter);

我收到错误消息

java.lang.NullPointerException: Attempt to invoke interface method 'void com.personal.anton.notes.recycle.NotesAdapter$CustomClickListener.onItemClickListener(android.view.View, int)' on a null object reference
    at com.personal.anton.notes.recycle.NotesAdapter$1.onClick(NotesAdapter.java:72)

public class NotesAdapter extends Adapter<NotesAdapter.NotesHolder> {

private List<Notes> notesList;
private NotesHandler notesHandler;
private Context context;
private int position;

public int getPosition() {
    return position;
}

public void setPosition(int position) {
    this.position = position;
}

public CustomClickListener listener;

public interface CustomClickListener{
    void onItemClickListener(View view, int position);
    void onItemLongClickListener(View view, int position);
}

public NotesAdapter(CustomClickListener listener){
    this.listener = listener;
}

public NotesAdapter(Context context, List<Notes> notesList){
    this.notesList = notesList;
    this.context = context;

    notesHandler = new NotesHandler(context);
}

@NonNull
@Override
public NotesHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    final View itemView = LayoutInflater.from(parent.getContext()).
            inflate(R.layout.view_row, parent, false);
    return new NotesHolder(itemView);
}

@Override
public void onBindViewHolder(@NonNull final NotesHolder holder, final int position) {
    Notes notes = notesList.get(position);
    holder.tvText.setText(notes.getText());
    holder.tvDate.setText(notes.getDate());

    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            listener.onItemClickListener(v, position);
        }
    });

    holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            listener.onItemLongClickListener(v, position);
            return true;
        }
    });

}

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

public void removeItem(int position){

    notesHandler.deleteNotes(new Notes(notesList.get(position).getId()));

    notesList.remove(position);

    notifyItemInserted(position);
}

public class NotesHolder extends ViewHolder implements OnCreateContextMenuListener{

    TextView tvText, tvDate;
    RelativeLayout foreground, background;

    NotesHolder(View itemView) {
        super(itemView);

        tvText = itemView.findViewById(R.id.tv_text);
        tvDate = itemView.findViewById(R.id.tv_date);

        foreground = itemView.findViewById(R.id.liner_foreground);
        background = itemView.findViewById(R.id.liner_background);

        //itemView.setOnCreateContextMenuListener(this);
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, final View v, ContextMenuInfo menuInfo) {
        menu.add(0, R.id.move, 0, R.string.move_widget);
    }
}

}

onClick和onLongClick似乎是并行触发的

1 个答案: