android - SharedElements 在 RecyclerView 中的不良影响

Question

我有一个带有 RecyclerView(SuperSlim 库)的 Activity 和一个详细 Activity ，当我单击该列表中的一个项目时，详细 Activity 将打开。问题是当我返回时，我试图将点击的元素设置为列表中的第一个可见元素，但我得到了这个可怕的动画:

这是我的 onActivityReenter()

    @Override
public void onActivityReenter(int resultCode, Intent data) {
    super.onActivityReenter(resultCode, data);
    Log.d(TAG, "onActivityReenter() called with: resultCode = [" + resultCode + "], data = [" + data + "]");

    mTmpReenterState = new Bundle(data.getExtras());
    int startingPosition = mTmpReenterState.getInt(EXTRA_STARTING_ITEM_POSITION);
    int currentPosition = mTmpReenterState.getInt(EXTRA_CURRENT_ITEM_POSITION);

    mRecycler.scrollToPosition(currentPosition);
    postponeEnterTransition();
    mRecycler.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
        @Override
        public boolean onPreDraw() {
            mRecycler.getViewTreeObserver().removeOnPreDrawListener(this);
            // TODO: figure out why it is necessary to request layout here in order to get a smooth transition.
            mRecycler.requestLayout();
            startPostponedEnterTransition();

            return true;
        }
    });
}

还有我的 SharedElementCallback:

    private final SharedElementCallback exitTransitionCallBack = new SharedElementCallback() {
    @Override
    public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {

        if (mTmpReenterState == null) {
            // If mTmpReenterState is null, then the activity is exiting.
            View navigationBar = findViewById(android.R.id.navigationBarBackground);
            View statusBar = findViewById(android.R.id.statusBarBackground);
            if (navigationBar != null) {
                names.add(navigationBar.getTransitionName());
                sharedElements.put(navigationBar.getTransitionName(), navigationBar);
            }
            if (statusBar != null) {
                names.add(statusBar.getTransitionName());
                sharedElements.put(statusBar.getTransitionName(), statusBar);
            }
        } else {
            int startingPosition = mTmpReenterState.getInt(EXTRA_STARTING_ITEM_POSITION);
            int currentPosition = mTmpReenterState.getInt(EXTRA_CURRENT_ITEM_POSITION);
            if (startingPosition != currentPosition) {
                // If startingPosition != currentPosition the user must have swiped to a
                // different page in the DetailsActivity. We must update the shared element
                // so that the correct one falls into place.
                sharedElements.clear();
                sharedElements.put("number", mLayoutManager.findViewByPosition(currentPosition).findViewById(R.id.text_number));
                sharedElements.put("day", mLayoutManager.findViewByPosition(currentPosition).findViewById(R.id.text_day));
                sharedElements.put("recycler", mLayoutManager.findViewByPosition(currentPosition + 1).findViewById(R.id.recycler));
            }

            mTmpReenterState = null;
        }
    }
};

我认为问题在于 Activity 尝试制作从原始项目位置到列表顶部的动画，但我不知道如何避免这种情况。

有谁知道如何解决这个问题？

提前谢谢大家!!!

Answer 1

一段时间后，我意识到我正在使用 LocalBroadcast 的 notifyItemChanged(int) 和标准的 recyclerView 更新 Main Activity 列表的问题 动画造成了这个故障。我使用以下方法解决问题:

  RecyclerView.setItemAnimator(null) 

因为标准不起作用

  ((SimpleItemAnimator) RecyclerView.getItemAnimator())
                          .setSupportsChangeAnimations(false)

所以问题与SharedElements无关。