Question

我正在构建一个音乐播放器应用并使用RecyclerView。当我从列表中选择一首歌曲时，文本（歌曲名称）开始水平滚动。如果我然后垂直滚动，要查找列表中的其他歌曲，然后滚动回正在播放的歌曲，水平滚动已停止，这是不希望的。

当我按下列表中的项目时，我将该视图保存在实例变量中（以后在更改歌曲时使用）并设置hasTransientState(true)。水平滚动的视图（ScrollTextView）是自定义的。按下某个项目时会调用方法playPauseStop。

对我而言，即使我在按下的视图上设置hasTransientState(true)，我的adapater-class中的onBindViewHolder也会被调用。

我设法使用ListView定期setHasTransientState(true)来避免此问题，但是如何使用RecyclerView来避免此问题？非常感谢任何帮助。

public class TrackListFragment extends Fragment {

    private Context mContext;
    private RecyclerView mRecyclerView;
    private TrackAdapter mTrackAdapter;
    private IPlayer mPlayer;
    private int mCurrentTrack = -1;

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        mContext = context;
        mPlayer = new Player(context);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.recycler_view_layout, container, false);
        mRecyclerView = (RecyclerView) view.findViewById(R.id.recycler_view);

    //mRecyclerView.getRecycledViewPool().setMaxRecycledViews(0, 3);

        Bundle bundle = getArguments();
        ArrayList<Track> tracks = null;
        if (bundle != null) {
             tracks = bundle.getParcelableArrayList("Tracks");
        }

         mTrackAdapter = new TrackAdapter(tracks, mContext);

         RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(mContext);
         mRecyclerView.setLayoutManager(mLayoutManager);
         mRecyclerView.setAdapter(mTrackAdapter);

         mRecyclerView.addOnItemTouchListener(new RecyclerTouchListener(mContext, mRecyclerView, new RecyclerTouchListener.IClickListener() {
        @Override
        public void onClick(View view, int position) {
            playPauseStop(view, position);
        }

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

        }
    }));
    return view;
}

private ScrollTextView mStv;
private RelativeLayout mRelativeLayout;

/**
 * mCurrentTrack is initially -1,
 * and set to -1 when media player is stopped.
 * @param position
 */
public void playPauseStop(View view, int position) {

    int firstViewItemIndex = ((LinearLayoutManager)mRecyclerView.getLayoutManager()).findFirstVisibleItemPosition();
    int screenIndex = position - firstViewItemIndex;

    ScrollTextView stv = null;
    RelativeLayout relativeLayout = (RelativeLayout)mRecyclerView.getChildAt(screenIndex);


    for(int i = 0; i < 2; i++) {
        if(relativeLayout.getChildAt(i) instanceof ScrollTextView) {
            stv = (ScrollTextView) relativeLayout.getChildAt(i);
        }
    }

        if(mCurrentTrack == position && mPlayer.isPlaying()) {
            mPlayer.pause();
            stv.pauseScroll();
        } else if(mCurrentTrack == position && !mPlayer.isPlaying()) {
            // Start after pause
            mPlayer.play();
            stv.resumeScroll();
        } else if(mCurrentTrack != position && mPlayer.isPlaying()) {
            // Stop playing track
            mPlayer.stop();

            // Start new track
            mPlayer = new Player(mContext);
            String itemData = mTrackAdapter.getItem(position);
            mPlayer.startPlayThread(itemData);

            mStv.stopScrolling();
            mStv.setTextColor(Color.BLUE);
            mRelativeLayout.setHasTransientState(false);

            mStv = stv;

            stv.startScroll();
            stv.setTextColor(Color.RED);
            relativeLayout.setHasTransientState(true);
            mRelativeLayout = relativeLayout;
            mCurrentTrack = position;
       }

       if(mCurrentTrack == -1) { // Initial. Start first track.
            mStv = stv;

            mCurrentTrack = position;
            String itemData = mTrackAdapter.getItem(position);
            mPlayer.startPlayThread(itemData);
            stv.startScroll();
            stv.setTextColor(Color.RED);

            relativeLayout.setHasTransientState(true);
            mRelativeLayout = relativeLayout;
            //mRelativeLayout.setHasTransientState(true);
        }
    }

}

我的适配器：

public class TrackAdapter extends RecyclerView.Adapter<TrackAdapter.MyViewHolder> {

private List<Track> mTracks;
private Context mContext;

public class MyViewHolder extends RecyclerView.ViewHolder {

        public TextView mTitle, mArtist;
        public ScrollTextView mScrollTextView;

        public MyViewHolder(View view) {
             super(view);
             mScrollTextView = (ScrollTextView) view.findViewById(R.id.scroll_track);
             mArtist = (TextView) view.findViewById(R.id.track_artist);
             mTitle =  (TextView) view.findViewById(R.id.track_duration);
        }

    }

    public TrackAdapter(List<Track> tracks, Context context) {
         mContext = context;
         mTracks = tracks;
    }

    public String getItem(int position) {
          return mTracks.get(position).getLocation();
    }

    @Override
    public TrackAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
         View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.track_list_layout, parent, false);
         return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(TrackAdapter.MyViewHolder holder, int position) {
         Track track = mTracks.get(position);
         holder.mScrollTextView.setTextColor(Color.BLUE);
         holder.mScrollTextView.setBackgroundColor(Color.BLACK);
         holder.mScrollTextView.setVisibility(View.VISIBLE);
         holder.mScrollTextView.setText(track.getTitle());
         holder.mArtist.setText(track.getArtist());
        //holder.setIsRecyclable(false);
    }

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

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

XML RecyclerView：

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:showIn="@layout/activity_main"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
         android:id="@+id/recycler_view"
         android:scrollbars="vertical"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />

</LinearLayout>

XML歌曲项目视图

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="match_parent"
     android:layout_height="wrap_content">

<package.name.custom.ScrollTextView
    android:id="@+id/scroll_track">

</package.name.custom.ScrollTextView>

    <TextView
        android:id="@+id/track_artist"
        android:layout_below="@id/scroll_track"
         />

    <TextView
        android:id="@+id/track_duration"
         />

</RelativeLayout>

如何防止单个动画视图回收。 RecyclerView

0 个答案: