错误java.lang.IllegalStateException：位置无效

Question

我正在尝试在1个提供程序（Content Provider）中开发2个应用程序，但是我编写的代码有问题，例如下面的脚本和logcat，我将NoteAdaper放在第一个应用程序中，以显示通过sqlite输入的数据，回收器视图，但是第一个或第二个应用程序无法显示输入的数据，是否有解决此问题的方法？

public class NoteAdapter extends RecyclerView.Adapter<NoteAdapter.NoteViewHolder> {
private Cursor listNotes;
private Activity activity;

public NoteAdapter(Activity activity){
    this.activity = activity;
}

public void setListNote(Cursor listNotes) {
    this.listNotes = listNotes;
}

@Override
public NoteViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_note, parent,false);
    return new NoteViewHolder(view);
}

@Override
public void onBindViewHolder(NoteViewHolder holder, int position) {
    final Note note = getItem(position);
    holder.tvTitle.setText(note.getTitle());
    holder.tvDescription.setText(note.getDescription());
    holder.tvDate.setText(note.getDate());
    holder.cvNote.setOnClickListener(new CustomOnItemClickListener(position, new CustomOnItemClickListener.OnItemClickCallback() {
        @Override
        public void onItemClicked(View view, int position) {
            Intent intent = new Intent(activity, FormAddUpdateActivity.class);

            Uri uri = Uri.parse(CONTENT_URI+"/"+note.getId());
            intent.setData(uri);
            activity.startActivityForResult(intent,FormAddUpdateActivity.REQUEST_UPDATE);
        }
    }));
}

@Override
public int getItemCount() {
    if(listNotes == null) return 0;
    return listNotes.getCount();
}

private Note getItem(int position){
    if (listNotes.moveToPosition(position)){
        throw new IllegalStateException("Position invalid");
    }
    return new Note(listNotes);
}

class NoteViewHolder extends RecyclerView.ViewHolder{
    TextView tvTitle, tvDescription, tvDate;
    CardView cvNote;

    NoteViewHolder(View itemView){
        super(itemView);
        tvTitle = (TextView)itemView.findViewById(R.id.tv_item_title);
        tvDescription = (TextView)itemView.findViewById(R.id.tv_item_description);
        tvDate = (TextView)itemView.findViewById(R.id.tv_item_date);
        cvNote = (CardView)itemView.findViewById(R.id.cv_item_note);
    }
}
}

Logcat：

java.lang.IllegalStateException：位置无效在com.project.ichwan.provider.adapter.NoteAdapter.getItem（NoteAdapter.java:68）在com.project.ichwan.provider.adapter.NoteAdapter.onBindViewHolder（NoteAdapter.java:44）在com.project.ichwan.provider.adapter.NoteAdapter.onBindViewHolder（NoteAdapter.java:24）在androidx.recyclerview.widget.RecyclerView $ Adapter.onBindViewHolder（RecyclerView.java:7065）在androidx.recyclerview.widget.RecyclerView $ Adapter.bindViewHolder（RecyclerView.java:7107）在androidx.recyclerview.widget.RecyclerView $ Recycler.tryBindViewHolderByDeadline（RecyclerView.java:6012）在androidx.recyclerview.widget.RecyclerView $ Recycler.tryGetViewHolderForPositionByDeadline（RecyclerView.java:6279）

Answer 1

来自Cursor.moveToPosition文档

如果请求目标可到达，则此方法将返回true，否则，将返回false。

看起来您应该将listNotes.moveToPosition（position）反转：

private Note getItem(int position){
    if (!listNotes.moveToPosition(position)){
        throw new IllegalStateException("Position invalid");
    }
    return new Note(listNotes);
}