Android 共享元素 fragment 转换 : return transition not working

Question

在我的项目中，我使用 RecyclerView 来显示带有缩略图的项目列表。当用户点击一个项目时，一个 DetailView 被打开，图像显示在顶部。我正在尝试在这些 fragment 之间共享一些元素，但过渡仅在进入细节 fragment 时起作用，而不是在从细节 fragment 返回时起作用。

在我的 ListAdapter 中，我设置了 TransitionName 并在用户点击某个项目时通知 ListFragment:

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        viewHolder.image.setTag(Constants.SHARED_NAME_IMAGE + item.itemId);
}

点击事件:

@OnClick(R.id.root)
 public void onClickedItem() {
        List<Pair<View, String>> sharedElements = new ArrayList<>();
        sharedElements.add(new Pair<View, String>(image, (String) image.getTag()));
        interactionListener.onItemSelected(data.get(getAdapterPosition() - headerItemCount).type, data.get(getAdapterPosition() - headerItemCount).itemId, sharedElements);
 }

然后在 ListFragment 中启动 DetailFragment:

public void navigateToFragment(Fragment curFragment, Fragment nextFragment,
                               boolean addToBackStack, List<Pair<View, String>> sharedElements) {
    if (nextFragment == null) {
        return;
    }
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && sharedElements != null && curFragment != null) {
        // Setup transition on first fragment
        curFragment.setSharedElementEnterTransition(TransitionUtil.getReturnTransition(this));
        curFragment.setSharedElementReturnTransition(TransitionUtil.getEnterTransition(this));
        curFragment.setEnterTransition(null);
        curFragment.setExitTransition(null);

        // Setup transition on second fragment
        nextFragment.setSharedElementEnterTransition(TransitionUtil.getEnterTransition(this));
        nextFragment.setSharedElementReturnTransition(TransitionUtil.getReturnTransition(this));
        nextFragment.setEnterTransition(null);
        nextFragment.setExitTransition(null);

        // Add second fragment by replacing first
        FragmentTransaction ft = getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.container, nextFragment);
        if (addToBackStack) {
            ft.addToBackStack("fragment");
        }

        for (Pair<View, String> sharedElement : sharedElements) {
            ViewCompat.setTransitionName(sharedElement.first, sharedElement.second);
            ft.addSharedElement(sharedElement.first, sharedElement.second);
        }

        // Apply the transaction
        ft.commit();
    } else {
        FragmentTransaction ft = getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.container, nextFragment);
        if (addToBackStack) {
            ft.addToBackStack("fragment");
        }
        ft.commit();
    }
}

最后，我在 DetailFragment 的 onCreateView() 中设置当前转换名称(因为它取决于 itemId):

ViewCompat.setTransitionName(header, Constants.SHARED_NAME_IMAGE + itemId);

Answer 1

我刚刚解决了这个问题:有两个问题:

1. 我已经覆盖了我的列表适配器(因此转换名称已被删除)
2. 我还没有在 onBindViewHolder 中设置转换名称

为了解决 #1，我像这里更改了 setUpList(){...}(第一个 if 很重要!):

 private void setupList() {
    if (adapter != null) {
        list.setAdapter(adapter);
        linearLayoutManager = new LinearLayoutManager(getActivity());
        list.setLayoutManager(linearLayoutManager);
        setScrollListener();
        return;
    }

    refreshLayout.setColorSchemeColors(ResourcesCompat.getColor(getResources(), R.color.main_color_2, getActivity().getTheme()));
    refreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            loadList(true);
        }
    });

    adapter = new ListAdapter((int) (DisplayUtils.getWidth(getActivity()) * 0.6), this);
    list.setAdapter(adapter);

    linearLayoutManager = new LinearLayoutManager(getActivity());
    list.setLayoutManager(linearLayoutManager);

    refreshLayout.post(new Runnable() {
        @Override
        public void run() {
            refreshLayout.setRefreshing(true);
            loadFilterItems();

为了解决#2，我只是将 setTag(..) 替换为 setTransitionName(..)

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                vh.image.setTransitionName(Constants.SHARED_NAME_IMAGE + item.itemId);
            }

在我的 onClick 方法中:

 List<Pair<View, String>> sharedElements = new ArrayList<>();
 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            sharedElements.add(new Pair<View, String>(image, image.getTransitionName()));
        }
 interactionListener.onItemSelected(data.get(getAdapterPosition() - headerItemCount).type, data.get(getAdapterPosition() - headerItemCount).itemId, sharedElements);