Android：在LinearLayout（性能）中重复一个复杂的视图

Question

I m trying to create an application that need to show a list of VideoViews inside a complex layout. The concept is very similar to Instagram and Facebook application. The Home screen with a bunch of videos and other stuff.

I've created a view composed by a toolbarr with three items, A videoView under the toolbar, and a bottomBar under the videoview with some textviews and imageviews.

I inflate this view dinamically inside a simple Vertical LinearLayout. To stress as little as possible the processor, I create ten views at a time .. Once I reach the end of the scrollBar I add another 15 and so on. Of course I don't initialize any video, I just set videoView Background with a Bitmap specially resized using inScale, inSampleSize and inDensity parameters. The concept is identical to Instagram. The problem comes when I reach an amount of 40 or 50 views.. It starts lag so bad.

This is how I inflate the layout:

View videoView = getLayoutInflater().inflate(R.layout.post_layout_2, null);

    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.MATCH_PARENT,
            RelativeLayout.LayoutParams.MATCH_PARENT
    );
    params.setMargins(0, 25, 0, 0);
    videoView.setLayoutParams(params);

    //Initialize components
    CircleImageView profImg = (CircleImageView) videoView.findViewById(R.id.post_profile_image);
    TextView postUsername = (TextView) videoView.findViewById(R.id.post_username);
    TextView postChallengeTitile = (TextView) videoView.findViewById(R.id.post_challenge_title);
    TextView postViews = (TextView) videoView.findViewById(R.id.post_views_count);
    TextView postLikes = (TextView) videoView.findViewById(R.id.post_like_count);

    //Fill components
    profImg.setImageBitmap(imgProfile);
    postUsername.setText("@"+username);
    postChallengeTitile.setText("#"+ challengeTitle);
    postViews.setText(String.valueOf(NumberFormat.getNumberInstance(Locale.US).format(views)));
    postLikes.setText(String.valueOf(NumberFormat.getNumberInstance(Locale.US).format(count)));
    cont.addView(videoView);


    final TextView durationTxt = (TextView) videoView.findViewById(R.id.video_duration_txt);
    final VideoView video = (VideoView) videoView.findViewById(R.id.videoView2);
    final ProgressBar progressDialog = (ProgressBar) videoView.findViewById(R.id.progressBar);
    //final String pathVideo = "android.resource://" +  getActivity().getPackageName() + "/" +  R.raw.mot;
    final String pathVideo = "https://videoLink";
    final Uri uri  = Uri.parse(pathVideo);


    BitmapFactory.Options myBit = new BitmapFactory.Options();
    myBit.inSampleSize = calculateInSampleSize(myBit, 300, 350);
    myBit.inScaled = true;
    myBit.inDensity = 600;
    myBit.inTargetDensity = 300* myBit.inSampleSize;
    Bitmap resize = BitmapFactory.decodeResource(getResources(), R.drawable.foto_test, myBit);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
        video.setBackground(new BitmapDrawable(getResources(), resize));
    }

I was wondering how does Instagram load all that number of videos without lag? Is there some tricks I can use?

Answer 1

That is the classic use case for RecyclerView . If will inflate enough views to fill the screen, when you scroll down will reuse the created views.

Another option is Litho from Facebook. Here is an article from Facebook about how they are doing it.