无法更改文本视图的可见性

Question

每当我播放一首歌曲时，我的“播放”按钮都会隐藏并且“停止”可见，但是当我单击其他视图的播放时，以前的视图应该从停止变为播放而不会发生

    List<firebaseDatum> dataList;
    Context activity;
    String image, title;
    // Media Player
    private MediaPlayer mediaplayer = new MediaPlayer();

    //itemclicklistener listener;
    public Recycler_Adapter(Context activity, List<firebaseDatum> dataList) {
        this.dataList = dataList;
        this.activity = activity;
//        this.listener=itemclicklistener;
    }

    public Recycler_Adapter(mainActivity activity, Object value, long childrenCount) {
    }


    @Override
    public MyviewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.recycler, parent, false);

        MyviewHolder mviewHolder = new MyviewHolder(itemView);

        return mviewHolder;
    }

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

        image = dataList.get(position).getImage();
        title = dataList.get(position).getTitle();
        holder.tv_title.setText(title);
        Picasso.with((Context) activity).load(image).placeholder(R.drawable.no_cover).into(holder.iv_albumart);
        if (!mediaplayer.isPlaying()) {
            holder.tv_play.setVisibility(View.VISIBLE);
            holder.tv_pause.setVisibility(View.GONE);
            holder.progressbar.setVisibility(View.GONE);
        }

    }

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

    public class MyviewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        public TextView tv_title, tv_play, tv_pause;
        public ImageView iv_albumart;
        TextView tv_download_button;
        RelativeLayout rl_info;
        ProgressBar progressbar;

        public MyviewHolder(View itemView) {
            super(itemView);
            tv_title = itemView.findViewById(R.id.tv_title);
            iv_albumart = itemView.findViewById(R.id.iv_albumart);
            tv_download_button = itemView.findViewById(R.id.iv_download_button);
            rl_info = itemView.findViewById(R.id.rl_info);
            tv_play = itemView.findViewById(R.id.tv_play);
            tv_pause = itemView.findViewById(R.id.tv_pause);
            progressbar = itemView.findViewById(R.id.progress);
            tv_download_button.setOnClickListener(this);
            rl_info.setOnClickListener(this);
            tv_title.setOnClickListener(this);
            tv_play.setOnClickListener(this);
            tv_pause.setOnClickListener(this);
        }

        @SuppressLint("StaticFieldLeak")
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.iv_download_button:
                    Intent download = new Intent(Intent.ACTION_VIEW, Uri.parse(dataList.get(getAdapterPosition()).getSong()));
                    activity.startActivity(download);
                    break;
                case R.id.tv_title:
                case R.id.rl_info:
                    Intent youtube = new Intent(Intent.ACTION_VIEW, Uri.parse(dataList.get(getAdapterPosition()).getYtlink()));
                    activity.startActivity(youtube);
                    break;
                case R.id.tv_play:
                    new AsyncTask<Void, Void, Void>() {
                        @Override
                        protected void onPreExecute() {
                            tv_pause.setVisibility(View.GONE);
                            tv_play.setVisibility(View.GONE);
                            progressbar.setVisibility(View.VISIBLE);
//                            mediaplayer = new MediaPlayer();
                            mediaplayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                        }

                        @Override
                        protected Void doInBackground(Void... params) {
                            try {
                                mediaplayer.setDataSource(dataList.get(getAdapterPosition()).getSong());
                                mediaplayer.prepare();
                            } catch (IllegalArgumentException e) {
//                                tv_play.setVisibility(View.GONE);
//                                progressbar.setVisibility(View.GONE);
//                                tv_pause.setVisibility(View.VISIBLE);
                                e.printStackTrace();
                            } catch (SecurityException e) {
//                                tv_play.setVisibility(View.GONE);
//                                progressbar.setVisibility(View.GONE);
//                                tv_pause.setVisibility(View.VISIBLE);
                                e.printStackTrace();
                            } catch (IllegalStateException e) {
//                                tv_play.setVisibility(View.GONE);
//                                progressbar.setVisibility(View.GONE);
//                                tv_pause.setVisibility(View.VISIBLE);
                                e.printStackTrace();
                            } catch (IOException e) {
//                                tv_play.setVisibility(View.GONE);
//                                progressbar.setVisibility(View.GONE);
//                                tv_pause.setVisibility(View.VISIBLE);
                                e.printStackTrace();
                            }
                            mediaplayer.start();
                            return null;
                        }

                        protected void onPostExecute(Void result) {
                            tv_play.setVisibility(View.GONE);
                            progressbar.setVisibility(View.GONE);
                            tv_pause.setVisibility(View.VISIBLE);
                            mediaplayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                                @Override
                                public void onCompletion(MediaPlayer mp) {
                                    mediaplayer.release();
                                    tv_play.setVisibility(View.VISIBLE);
                                    progressbar.setVisibility(View.GONE);
                                    tv_pause.setVisibility(View.GONE);
                                }
                            });
                        }
                    }.execute();
                    break;
                case R.id.tv_pause:
                    if (mediaplayer.isPlaying()) {
                        mediaplayer.stop();
                        mediaplayer.release();
                        tv_pause.setVisibility(View.GONE);
                        tv_play.setVisibility(View.VISIBLE);
                    }
                    break;
            }
        }
    }
}

除此播放/停止可见性问题外，其他所有操作均正常。 非常感谢您的帮助。