Question

我有一个显示来自数据库的注释的Recycler视图，我在适配器中有一个onclick方法，因此我可以单击每个元素以显示一个对话框来编辑/删除/ make完成，我的问题是，一旦它执行了动作，因为它在适配器中，我如何让它刷新活动的recyclelerview？

适配器类

public class NoteDataAdapter extends RecyclerView.Adapter<NoteDataAdapter.RecyclerViewHolder> {


    ArrayList<NoteDataProvider> arrayList = new ArrayList<>();
    NoteDataAdapter(ArrayList<NoteDataProvider> arrayList)
    {
        this.arrayList = arrayList;
    }
    public static String doner;

    @Override
    public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_assignment_note_layout,parent, false);
        RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view);
        return recyclerViewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerViewHolder holder, int position) {


        NoteDataProvider noteDataProvider = arrayList.get(position);
        holder.id.setText(noteDataProvider.getId());
        holder.note.setText(noteDataProvider.getContent());
        holder.done.setText(noteDataProvider.getDone());
        String doneee = holder.done.getText().toString();
        final String yes = "Yes";
        doner = holder.done.getText().toString();

        if (doneee.equals("Yes"))

        {
            holder.note.setPaintFlags(holder.note.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
        }
        else {
           // nothing
        }

    }

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

    public static class RecyclerViewHolder extends RecyclerView.ViewHolder{

        TextView id, note, done;

        public NoteDataProvider item;

        RecyclerViewHolder(View view){
            super(view);
            id = (TextView)view.findViewById(R.id.note_id);
            note = (TextView)view.findViewById(R.id.note_content);
            done = (TextView)view.findViewById(R.id.note_done);

            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick( final View v) {

                    Toast.makeText(v.getContext(), "os version is: " + done.getText().toString()+ " " + doner , Toast.LENGTH_SHORT).show();
                    DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            switch (which){
                                case DialogInterface.BUTTON_POSITIVE:
                                    UserDbHelper userDbHelper;
                                    SQLiteDatabase sqLiteDatabase;
                                    userDbHelper = new UserDbHelper(v.getContext());
                                    sqLiteDatabase = userDbHelper.getReadableDatabase();
                                    userDbHelper.updateNote(id.getText().toString(), "Yes", sqLiteDatabase);

                                    break;

                                case DialogInterface.BUTTON_NEGATIVE:
                                    //Edit
                                    break;
                                case DialogInterface.BUTTON_NEUTRAL:
                                    //Delete
                                    userDbHelper = new UserDbHelper(v.getContext());
                                    sqLiteDatabase = userDbHelper.getReadableDatabase();
                                    userDbHelper.deleteAssignmentNote(id.getText().toString(), sqLiteDatabase);
                                    break;
                            }
                        }
                    };


                    AlertDialog.Builder builder = new AlertDialog.Builder(new ContextThemeWrapper(v.getContext(), R.style.myDialog));
                    builder.setMessage("What would you like to do?").setPositiveButton("Mark as done", dialogClickListener)
                            .setNegativeButton("Edit", dialogClickListener).setNeutralButton("Delete",dialogClickListener).show();
                }
            });



        }
    }
}

活动类recyclerview代码段

recyclerView = (RecyclerView)findViewById(R.id.assignment_notes_recyclerview);
        layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setHasFixedSize(true);
        adapter = new NoteDataAdapter(arrayList);
        recyclerView.setAdapter(adapter);
        UserDbHelper userDbHelper = new UserDbHelper(this);
        SQLiteDatabase sqLiteDatabase = userDbHelper.getReadableDatabase();

        Cursor cursor = userDbHelper.getAssignmentNotes( selected, sqLiteDatabase);

        cursor.moveToFirst();
        do {
            NoteDataProvider noteDataProvider = new NoteDataProvider(cursor.getString(0), cursor.getString(2), cursor.getString(3));
            arrayList.add(noteDataProvider);
        }while(cursor.moveToNext());
        userDbHelper.close();

Answer 1

您可以从适配器调用notifyItemInserted / Removed / Changed来告诉RecyclerView究竟发生了什么变化。有关详细信息，请参阅https://developer.android.com/reference/android/support/v7/widget/RecyclerView.Adapter.html。

Answer 2

使你的适配器abstrcat类：

public abstrcat class NoteDataAdapter extends...

并将类抽象方法添加到类中：

public abstract void delete();
public abstract void edit();

单击按钮

时调用这些方法

并在您的活动中实施它们

从适配器中的onclick刷新recyclerview

2 个答案: