RecycleView adapter data show wrong when scrolling too fast

问题:

I have a custom Recycle View adapter that list my items. in each Item I check database and draw some circles with colors.

when I scroll listview very fast every drawed data ( not title and texts) show wrongs! how I can manage dynamic View creation without showing wrong data?!

 @Override     public void onBindViewHolder(final ItemViewHolder itemViewHolder, int i) {          itemViewHolder.date.setText(items.get(i).getData()); // set the title          itemViewHolder.relative_layout_tag_place.addView(generateTagImages(items.get(i).getServerId()));  // had to generate a Relativelaout with   }

and this is importMenuTags():

   private RelativeLayout generateTagImages(String serverId) {          List color_list = new ArrayList<>();     RelativeLayout result = new RelativeLayout(context);     List list = db.getCardTags(serverId);          int i = 0;         for (String string : list) {             RelativeLayout rl = new RelativeLayout(context);             color_list.add(get_the_proper_color);             Drawable drawable = context.getResources().getDrawable(R.drawable.color_shape);             drawable.setColorFilter(Color.parseColor(dao.getTagColor(string)), PorterDuff.Mode.SRC_ATOP);             RelativeLayout.LayoutParams lparams = new RelativeLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);             lparams.addRule(RelativeLayout.ALIGN_PARENT_START);             lparams.setMargins(i, 0, 0, 0);             lparams.width = 35;             lparams.height = 35;             rl.setLayoutParams(lparams);              if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {                 rl.setBackground(drawable);             } else {                 rl.setBackgroundDrawable(drawable);             }              result.addView(rl);             i = i + 25;          }       return result; }

I also had the same problem in simple custom adapter that it's solved by moving my function place out of

if (convertView == null) {

this is the link.

回答1:

As per seeing in your code, I found your relative layout must be showing some extra data while scrolling. And thats because of recycling of views. Here

   public void onBindViewHolder(final ItemViewHolder itemViewHolder, int i) {              itemViewHolder.date.setText(items.get(i).getData()); // set the title              itemViewHolder.relative_layout_tag_place.addView(generateTagImages(items.get(i).getServerId()));  // had to generate a Relativelaout with  //Problem is here.

Suppose you added some child views in above holde.relative_layout , and this ViewHodler is recyclerd and provided to another item view, It already have all previously added views in it. and you are adding new child view with them. Hope you understand your problem.

Solution: Very easy one. remove all previsousley added view in onBindViewHolder

   public void onBindViewHolder(final ItemViewHolder itemViewHolder, int i) {              itemViewHolder.date.setText(items.get(i).getData()); // set the title       itemViewHolder.relative_layout_tag_place.removeAllViews();    itemViewHolder.relative_layout_tag_place.addView(generateTagImages(items.get(i).getSe