java - 显示后如何检测每个 RecyclerView item

Question

我想检测我的 RecylerView 中的每个项目显示给用户后。

基本上，我试图在每个项目加载到屏幕上后播放声音。

但是我无法检测到每个项目何时加载到屏幕上!有没有我必须调用的方法来检测呈现的每个项目

E.g 1st RecyclerView item displayed -> play sound
    2st RecyclerView item displayed -> play sound...

我的 Adapter 类看起来像这样 -

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

    private List<Multiples> items = new ArrayList<>();

    private Context ctx;
    private OnItemClickListener mOnItemClickListener;
    private int animation_type = 0;
    .........
    .........

我正在从 onCreated() 方法调用此 initComponent() 方法。您能否就我应该如何实现上述目标提出建议？

private void initComponent() {
    recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setHasFixedSize(true);
    items = DataGenerator.getPeopleData(this,of,value);
    setAdapter();

    /* MediaPlayer mp=MediaPlayer.create(this, R.raw.sword);
    if (mp.isPlaying()) {
        mp.stop();
        mp.release();
        mp = MediaPlayer.create(this, R.raw.sword);
    } mp.start();*/
}

private void setAdapter() {
    // Set data and list adapter
    mAdapter = new AdapterListAnimation(this, items, animation_type);
    recyclerView.setAdapter(mAdapter);

    // on item list clicked
    mAdapter.setOnItemClickListener(new AdapterListAnimation.OnItemClickListener() {
        @Override
        public void onItemClick(View view, com.math.multiplication.model.Multiples obj, int position) {
            Snackbar.make(parent_view, "Item " + obj.first + " clicked", Snackbar.LENGTH_SHORT).show();
        }
    });
}

Answer 1

您需要覆盖 onViewAttachedToWindow 和 onViewDetachedFromWindow。但是为了检测 holer 类型，你需要像这样的 getItemViewType():

public class PostAdapter extends RecyclerView.Adapter {

@Override
public int getItemViewType(int position) {
    switch (types.get(position)){
        case 1:
            return 1;
        case 2:
            return 2;
        default:
            return position;


    }
}
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
    super.onViewAttachedToWindow(holder);
    if (holder.getItemViewType() == 1){
        //play song

    }

}

@Override
public void onViewDetachedFromWindow(@NonNull RecyclerView.ViewHolder holder) {
    super.onViewDetachedFromWindow(holder);
    if (holder.getItemViewType() == 1){
        //pause song

    }
}