Recycler View 在滚动时不使用提供的布尔值一致地更新视图

Question

I have a dataset I use to create a recycler view and the elements in it have a "solved" Boolean value. When the recyclerview is initialized everything displays correctly. When I scroll through slowly for the most part the corresponding image is displayed correctly but a few of the images blink in and out of view. If I scroll very fast then everything essentially gets messed up.

private class RegularCrimeHolder extends CrimeHolder implements View.OnClickListener{
    private Crime mCrime;
    private TextView mTitleTextView;
    private TextView mDateTextView;
    public RegularCrimeHolder(LayoutInflater inflater, ViewGroup parent) {

        super(inflater.inflate(R.layout.list_item_crime, parent, false));
        mTitleTextView = this.itemView.findViewById(R.id.crime_title);
        mDateTextView = this.itemView.findViewById(R.id.crime_date);
        mSolved = this.itemView.findViewById(R.id.solved);

        itemView.setOnClickListener(this);
    }


    //Optional
    public void bind(Crime crime){
        mCrime = crime;
        mTitleTextView.setText(mCrime.getTitle());
        mDateTextView.setText(mCrime.getDate().toString());
        mSolved.setVisibility(crime.isSolved()? View.VISIBLE : View.GONE);
    }


    @Override
    public void onClick(View view) {
        //Toast toast = Toast.makeText(getActivity(), mCrime.getTitle() + " clicked!", Toast.LENGTH_SHORT);
        //toast.show();

        Intent intent = CrimeViewPagerActivity.newIntent(mCrime.getID(), getContext(), CrimeLab.GetIndex(mCrime));
        startActivityForResult(intent, REQUEST_CRIME);
    }
}

private class CrimeAdapter extends RecyclerView.Adapter<CrimeHolder>{

    private List<Crime> mCrimes;

    public CrimeAdapter(List<Crime> crimes){
        mCrimes = crimes;
        this.setHasStableIds(true);
    }

    @Override
    public long getItemId(int position){
        return position;
    }

    @Override
    public CrimeHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
        if(viewType == 0)
            return new RegularCrimeHolder(layoutInflater, viewGroup);
        else
            return new BadCrimeHolder(layoutInflater, viewGroup);
    }

    @Override
    public int getItemViewType(int position) {
        if(mCrimes.get(position).RequiresPolice())
            return 1;
        else
            return 0;
    }

    @Override
    public void onBindViewHolder(@NonNull CrimeHolder crimeHolder, int i) {
        Crime crime = mCrimes.get(i);
        crimeHolder.bind(crime);
    }

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

}

Answer 1

Don't worry! Cool! In your adapter, just do the below things

Kotlin

 override fun getItemId(position: Int): Long {
    return position.toLong()
  }
override fun getItemViewType(position: Int): Int {
    return position
}

Java

@Override
public long getItemId(int position) {
    return position;
}

 @Override
public int getItemViewType(int position) {
    return position;
}

Answer 2

Your sample code lacks detail. Post the full adapter viewholder and item layout code.

But if I had to guess here, your layout is messed up and your onViewRecycled isn't cleaning up correctly.

For example, say a viewholder was just used and the visibility was set to visible. Now when this viewholder is recycled and re bound, what you'll see is a flicker. Because the view in question is visible from that last bind and it needs to hide itself in this bind.

What you want to do is inside your onViewRecycled, you want to set the visibility set to gone so that when viewholders are reused, there are no flickers.