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androidlistviewandroid-studioandroid-mediaplayerandroid-cursor

Listview hangs when I scroll in android


I am creating music player app and I used cursor to get songs from local storage. I successfully displayed songs along with album arts but when I scroll list it hangs. What should I do to solve this problem.

This is my cursor :

cursor = getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null,MediaStore.Audio.AudioColumns.DURATION+">0", null, sortOrder);

Here is class which binds songs and album art with listview fields :

private class MediaCursorAdapter extends SimpleCursorAdapter {

    String backgroundColor = "white";
    String someOtherBackgroundColor = "#F5F5F5";
    public MediaCursorAdapter(Context context, int layout, Cursor c) {
        super(context, layout, c,
                new String[]{MediaStore.MediaColumns.DISPLAY_NAME, MediaStore.MediaColumns.TITLE, MediaStore.Audio.AudioColumns.DURATION,MediaStore.Audio.Media.ALBUM_ID},
                new int[]{R.id.displayname, R.id.title, R.id.duration,R.id.iv_art});
    }

    public Bitmap getAlbumart(Context context, Long album_id){
        Bitmap bm = null;
        BitmapFactory.Options options = new BitmapFactory.Options();
        try{
            final Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");
            Uri uri = ContentUris.withAppendedId(sArtworkUri, album_id);
            ParcelFileDescriptor pfd = context.getContentResolver().openFileDescriptor(uri, "r");
            if (pfd != null){
                FileDescriptor fd = pfd.getFileDescriptor();
                bm = BitmapFactory.decodeFileDescriptor(fd, null, options);
                pfd = null;
                fd = null;
            }
        } catch(Error ee){}
        catch (Exception e) {}
        return bm;
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {


        if(cursor.getPosition() % 2 == 0)
        {
            view.setBackgroundColor(
                    Color.parseColor(backgroundColor));
        }
        else
        {
            view.setBackgroundColor(
                    Color.parseColor(someOtherBackgroundColor));
        }


        TextView title = (TextView) view.findViewById(R.id.title);
        TextView name = (TextView) view.findViewById(R.id.displayname);
        TextView duration = (TextView) view.findViewById(R.id.duration);
        ImageView iv_art = (ImageView) view.findViewById(R.id.iv_art);


        String a = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));



        Long l = Long.parseLong(a);

        Bitmap art = getAlbumart(songlist.this,l);
        if(art!=null)
        {
            iv_art.setImageBitmap(art);
        }
        else
        {
            iv_art.setImageResource(R.mipmap.app_splash_screen_icon);
        }

        long durationInMs = Long.parseLong(cursor.getString(
                cursor.getColumnIndex(MediaStore.Audio.AudioColumns.DURATION)));

        name.setText(cursor.getString(
                    cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME)));

        title.setText(cursor.getString(
                    cursor.getColumnIndex(MediaStore.MediaColumns.TITLE)));

        Utility d = new Utility();

        String durationInMin = d.convertDuration(durationInMs);

        duration.setText("" + durationInMin);

        view.setTag(cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DATA)));
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View v = inflater.inflate(R.layout.listitem, parent, false);

        bindView(v, context, cursor);

        return v;
    }
}

Here is the code which sets adapter of listview :

mediaAdapter = new MediaCursorAdapter(this, R.layout.listitem, cursor);

lv_songlist.setAdapter(mediaAdapter);

Solution

  • Every time you create a new row in your ListView you load the image from the storage on the UI-Thread. As loading data (especially images) from the storage is an operation that can take a little while it will block the UI-Thread from performing any work other than loading that image for a little while. This results in the "hanging" you experience.

    Best solution would be to offload the image loading onto a different Thread. You can do this either manually or using one of the wildly used Image Loading Libraries out there (Picasso, Glide, UniversalImageLoader) which can do the work for you.