android - 在Android中展开recyclerView时如何旋转图像

在我的应用程序中，我想展开和折叠recyclerView！
我可以展开和折叠recyclerView，为此，我使用以下库：https://github.com/thoughtbot/expandable-recycler-view

我想在单击recyclerView（展开或折叠）时旋转箭头图像！
我在viewHolder类中编写以下代码，但不起作用并且无法旋转箭头图像！
ParentViewHolder代码：

public class seasonParentViewHolder extends GroupViewHolder {

    private TextView row_epGuideParent_Title, row_epGuideParent_Count, row_epGuideParent_Date;
    private ImageView row_epGuideParent_arrowImg;

    public seasonParentViewHolder(View itemView) {
        super(itemView);
        row_epGuideParent_Title = (TextView) itemView.findViewById(R.id.row_epGuideParent_Title);
        row_epGuideParent_Count = (TextView) itemView.findViewById(R.id.row_epGuideParent_Count);
        row_epGuideParent_Date = (TextView) itemView.findViewById(R.id.row_epGuideParent_Date);
        row_epGuideParent_arrowImg = (ImageView) itemView.findViewById(R.id.row_epGuideParent_arrowImg);
    }

    public void setGenreTitle(ExpandableGroup title) {
        if (title instanceof ExpandableModel) {
            row_epGuideParent_Title.setText(title.getTitle());
            row_epGuideParent_Count.setText(((ExpandableModel) title).getCount());
            row_epGuideParent_Date.setText(((ExpandableModel) title).getDate());
        }
    }

    @Override
    public void expand() {
        animateExpand();
    }

    @Override
    public void collapse() {
        animateCollapse();
    }

    private void animateExpand() {
        RotateAnimation rotate =
                new RotateAnimation(360, 180, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
        rotate.setDuration(300);
        rotate.setFillAfter(true);
        row_epGuideParent_arrowImg.setAnimation(rotate);
    }

    private void animateCollapse() {
        RotateAnimation rotate =
                new RotateAnimation(180, 360, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
        rotate.setDuration(300);
        rotate.setFillAfter(true);
        row_epGuideParent_arrowImg.setAnimation(rotate);
    }
}

在库中称为展开和折叠：

public abstract class GroupViewHolder extends RecyclerView.ViewHolder implements OnClickListener {

  private OnGroupClickListener listener;

  public GroupViewHolder(View itemView) {
    super(itemView);
    itemView.setOnClickListener(this);
  }

  @Override
  public void onClick(View v) {
    if (listener != null) {
      if (listener.onGroupClick(getAdapterPosition())) {
        collapse();
      } else {
        expand();
      }
    }
  }

  public void setOnGroupClickListener(OnGroupClickListener listener) {
    this.listener = listener;
  }

  public void expand() {}

  public void collapse() {}

}

单击recyclerView（展开或折叠）时，如何解决此问题并旋转箭头图像？

最佳答案

TL; DR您必须对startAnimation()使用ImageView而不是setAnimation()。


  void setAnimation (Animation animation)
  
  设置要为此视图播放的下一个动画。如果你想要
  动画立即播放，使用
  startAnimation（android.view.animation.Animation）代替[...]


（引自developer.android.com/reference/android/view/View.html）

关于android - 在Android中展开recyclerView时如何旋转图像，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/45332523/