Android animating recyclerview

Question

我創建了一個包含「events」列表的recyclerview。這對於低於5的事件列表正常工作，但只要列表中有6個或更多事件，最後一個事件不會展開當點擊時，反而消失。關閉動畫也停止工作，列表中有6個以上的事件。

應該如何表現：

• 用戶點擊事件>視圖擴展到整個屏幕
• 用戶點擊展開事件>視圖摺疊回它的原始尺寸
• 用戶點擊，而另一個事件的事件
  ：展開>連接竊聽事件展開爲全屏

當前的行爲展開事件設置爲原來的高度3210

• 用戶點擊事件>所有視圖正確地擴大，除了在列表中的最後一個項目
• 用戶點擊展開的事件>查看倒塌，但沒有動畫
• 用戶點擊一個事件，而另一事件展開>展開事件崩塌，竊聽事件正確擴展
• 用戶點擊的最後一個事件列表>事件自敗（可能降低它的尺寸小於0）

我知道它可能有一些做的方式recyclerview再利用其觀點當他們不在屏幕上時。爲了解決這個問題，我使用eventId而不是列表中的位置來檢查tapped事件的位置，但這仍然留下了我上面討論的問題。

public class EventRecyclerAdapter extends RecyclerView.Adapter<EventRecyclerAdapter.ViewHolder> { 
    private Context c; 
    private List<Event> items = new ArrayList<>(); 
    private RelativeLayout container; 
    private int screenheight; 
    private EventListFragment eventListFragment; 
    private int expandedPosition = -1; 
    private static final String TAG = "EventRecyclerAdapter"; 

    public interface ItemClickedListener { 
     void itemClicked(int position); 
    } 

    private ItemClickedListener itemClickedListener; 

    public EventRecyclerAdapter(List<Event> itemlist, Context c, EventListFragment eventListFragment, ItemClickedListener listener) { 
     this.items = itemlist; 
     this.c = c; 
     this.eventListFragment = eventListFragment; 
     this.itemClickedListener = listener; 
    } 

    @Override 
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     // create a new view 
     View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, null); 

     WindowManager wm = (WindowManager) c.getSystemService(Context.WINDOW_SERVICE); 
     Display display = wm.getDefaultDisplay(); 
     Point size = new Point(); 
     display.getSize(size); 
     screenheight = size.y; 

     // Get the screen height from the device 
     Resources r = c.getResources(); 
     float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 80, r.getDisplayMetrics()); 
     screenheight -= px; 

     ViewHolder viewHolder = new ViewHolder(itemLayoutView); 
     return viewHolder; 
    } 

    // Replace the contents of a view (invoked by the layout manager) 
    @Override 
    public void onBindViewHolder(ViewHolder viewHolder, int position) { 
     Event event = items.get(position); 
     // - get data from your itemsData at this position 
     // - replace the contents of the view with that itemsData 
     viewHolder.tvName.setText(event.getName()); 
     viewHolder.tvLocation.setText(event.getLocation().getName()); 
     viewHolder.tvDate.setText(Helper.dateDoubleToString(event.getStartDate())); 
     viewHolder.tvTicketCount.setText(String.valueOf(event.getNumberOfTickets())); 
     viewHolder.background.setBackgroundColor(Color.GRAY); 
     viewHolder.eventId = event.getId(); 

     // Load the background image 
     if (event.getEventImageId() != null) { 
      Picasso.with(c).load(Helper.imageUrlString(event.getEventImageId())).into(viewHolder.background); 
      ColorMatrix matrix = new ColorMatrix(); 
      matrix.setSaturation(0); 

      ColorMatrixColorFilter filter = new ColorMatrixColorFilter(matrix); 
      viewHolder.background.setColorFilter(filter); 
     } 

     // Check if the view needs to be expanded, collapsed or just drawn normally. 
     if (expandedPosition == event.getId()) { 
      if (event.expanded) { 
       collapseView(viewHolder, event); 
      } else if (!event.expanded) { 
       expandView(viewHolder, position, event); 
      } 
     } else { 
      setContainerHeight(viewHolder, event); 
     } 
    } 

    private void expandView(final EventRecyclerAdapter.ViewHolder viewHolder, final int pos, Event event) { 
     ResizeAnimation resizeAnimation = new ResizeAnimation(
       viewHolder.container, 
       viewHolder.container.getHeight(), 
       screenheight 
     ); 
     resizeAnimation.setDuration(Constants.ANIMATION_SPEED); 
     resizeAnimation.setAnimationListener(new Animation.AnimationListener() { 
      @Override 
      public void onAnimationStart(Animation animation) { 
      } 

      @Override 
      public void onAnimationEnd(Animation animation) { 
       viewHolder.infoContainer.setVisibility(View.VISIBLE); 
       viewHolder.closeIcon.setVisibility(View.VISIBLE); 
       itemClickedListener.itemClicked(pos); 
      } 

      @Override 
      public void onAnimationRepeat(Animation animation) { 
      } 
     }); 
     viewHolder.itemView.startAnimation(resizeAnimation); 
     viewHolder.expanded = true; 

     event.expanded = true; 
    } 

    private void collapseView(final EventRecyclerAdapter.ViewHolder viewHolder, Event event) { 
     ResizeAnimation resizeAnimation = new ResizeAnimation(
       viewHolder.container, 
       viewHolder.container.getHeight(), 
       getContainerCollapsedHeight() 
     ); 
     resizeAnimation.setDuration(Constants.ANIMATION_SPEED); 

     viewHolder.infoContainer.setVisibility(View.INVISIBLE); 
     viewHolder.closeIcon.setVisibility(View.INVISIBLE); 
     viewHolder.itemView.startAnimation(resizeAnimation); 
     viewHolder.expanded = false; 
     event.expanded = false; 
} 

    private void setContainerHeight(EventRecyclerAdapter.ViewHolder viewHolder, Event event) { 
     viewHolder.container.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, getContainerCollapsedHeight())); 
     viewHolder.infoContainer.setVisibility(View.INVISIBLE); 
     viewHolder.closeIcon.setVisibility(View.INVISIBLE); 
     event.expanded = false; 
     viewHolder.expanded = false; 
    } 

    private int getContainerCollapsedHeight() { 
     int containerHeight; 
     // Define the item containers height 
     if (items.size() <= 3) { 
      containerHeight = screenheight/items.size(); 
     } else { 
      containerHeight = screenheight/3; 
     } 
     return containerHeight; 
    } 

    /** 
    * Clear all current data and swap add the new data list. 
    * The expanded position also gets reset 
    * @param events 
    */ 
    public void swap(List<Event> events) { 
     this.items.clear(); 
     this.items.addAll(events); 
     this.expandedPosition = -1; 

     Log.v(TAG,"SWAP SIZE : " + items.size()); 
     notifyDataSetChanged(); 
    } 

    // inner class to hold a reference to each item of RecyclerView 
    class ViewHolder extends RecyclerView.ViewHolder { 

     public TextView tvLocation, tvDate, tvTicketCount; 
     public TextView tvName; 
     public ImageView background; 
     public View container; 
     public View infoContainer; 
     public TextView closeIcon; 
     public int eventId; 
     public boolean expanded = false; 

     public ViewHolder(final View itemLayoutView) { 
      super(itemLayoutView); 

      tvName = (TextView) itemLayoutView.findViewById(R.id.tvName); 
      tvLocation = (TextView) itemLayoutView.findViewById(R.id.tvLocation); 
      tvDate = (TextView) itemLayoutView.findViewById(R.id.tvDate); 
      background = (ImageView) itemLayoutView.findViewById(R.id.background); 
      tvTicketCount = (TextView) itemLayoutView.findViewById(R.id.ticket_count); 
      container = itemLayoutView.findViewById(R.id.list_item_container); 
      infoContainer = itemLayoutView.findViewById(R.id.info_container); 
      closeIcon = (TextView) itemLayoutView.findViewById(R.id.close_icon); 

      infoContainer.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View view) { 
        Activity mainActivity = (Activity) c; 
        FragmentManager fm = mainActivity.getFragmentManager(); 
        //add 
        FragmentTransaction ft = fm.beginTransaction(); 
        ft.setCustomAnimations(R.animator.slide_to_top, R.animator.slide_from_bottom); 
        ft.addToBackStack(ft.toString()); 
        ft.add(R.id.content_frame, EventFragment.newInstance(items.get(getAdapterPosition())), Constants.EVENT_FRAGMENT_TAG); 
        //commit change 
        ft.commit(); 
       } 
      }); 

      container.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        expandedPosition = eventId; 
        notifyDataSetChanged(); 
       } 
      }); 
     } 
    } 

    // Return the size of your itemsData (invoked by the layout manager) 
    @Override 
    public int getItemCount() { 
     return items.size(); 
    } 
} 

我認爲這是某種方式運行collapseView方法，當我點擊的最後一個項目在列表中，導致其高度，成爲低於0。但我無法弄清楚爲什麼發生這種情況。 我希望有人能夠發現這裏有什麼問題。

Answer 1

您可以在OnClilck試試這個rec​​ycleview項目的

@Override 
public void onClick(View view) 
{ 
LayoutParams params = view.getLayoutParams(); 
    if (!large) 
     { 
      params.height = 2 * view.getHeight();  
     } else { 
      params.height = view.getHeight()/2; 
     } 
     large = !large; 
     view.setLayoutParams(params); 
}