flutter - 无法使用英雄动画 Flutter 找到正确的 Provider<>

Question

我正在推新 Route在我的图库文件中添加到详细信息文件 Hero动画片。一切都很好，但是当我调用 pop() 时在返回图库的详细信息文件中，我有一个 Provider错误 :

flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following ProviderNotFoundException was thrown building GalleryThumbnail(dirty, state:
flutter: _GalleryThumbnailState#9dc96):
flutter: Error: Could not find the correct Provider<GalleryViewModel> above this GalleryThumbnail Widget

这是我的画廊文件:

@override
  Widget build(BuildContext context) {
    return MultiProvider(
        providers: [
          ChangeNotifierProvider.value(value: galleryViewModel),
          ChangeNotifierProvider.value(value: galleryProvider)
        ],
        child: Scaffold(
            resizeToAvoidBottomInset: false,
            body: Stack(
              children: [
                Consumer<GalleryViewModel>(
                    builder: (context, model, child) =>
                        galleryViewModel.assetsList.length != 0 ? gallery() : emptyGallery()),

...

}


Widget gallery() {
    return Container(
      padding: EdgeInsets.only(left: 5, right: 5, top: 5),
      child: CupertinoScrollbar(
        child: GridView.builder(
          gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
              crossAxisCount: 3,
              crossAxisSpacing: 2,
              mainAxisSpacing: 2,
              childAspectRatio: 0.85,
            ),
          itemCount: galleryViewModel.assetsList.length,
          padding: EdgeInsets.only(bottom: Constants.navBarSize),
          physics: BouncingScrollPhysics(),
          shrinkWrap: true,
          itemBuilder: (context, index) {
            if(index >= galleryViewModel.assetsList.length-30) {
              galleryViewModel.onLoadMore(index);
            }
            return _galleryItem(index);
          },

        ),
      ),
    );
  }


Widget _galleryItem(int index) {
    return Stack(
      children: [
        Consumer<GalleryProvider>(
          builder: (context, model, child) {
            return Container(
              padding:
                  multipleSelection ? EdgeInsets.all(2) : EdgeInsets.all(0),
              decoration: multipleSelection ? BoxDecoration(
                      borderRadius: BorderRadius.circular(20),
                      border: Border.all(color: Colors.transparent , width: 2)) : BoxDecoration(),
              child: child,
            );
          },
            Hero(
            createRectTween: (Rect? begin, Rect? end) {
              RectTween _rectTween =
              RectTween(begin: begin, end: end);
              return _rectTween;
            },
            tag: galleryViewModel.assetsList[index].id,
            child:
          child: GalleryThumbnail(
            asset: galleryViewModel.assetsList[index],
           
            onTap: (data) {
              Navigator.push(context, MaterialPageRoute(builder: (context) {
                  return MediaEditorPage(
                      asset: galleryViewModel.assetsList[index],
                      bytes: data);
                }));
            },
          ),


...

}

当我在没有英雄或其他路线的情况下插入时，没有错误，我不知道为什么在英雄上方找不到提供者，我不会在导航器转换时通知任何提供者。
为什么我在这里收到供应商错误以及如何解决这个问题？
谢谢你的帮助

Answer 1

使用时Hero小部件，似乎有一个 Context问题。
这意味着当动画正在执行时，并且在目的地您正在调用 Provider.of<Model>(context) ，它不会找到正确的 Provider .
您只需像使用 Navigator 那样做即可在你的例子中给出:

Hero(
  createRectTween: (Rect? begin, Rect? end) {
    RectTween _rectTween =
    RectTween(begin: begin, end: end);
    return _rectTween;
  },
  tag: galleryViewModel.assetsList[index].id,
  child: ChangeNotifierProvider.value(
    value: galleryViewModel,
    child: GalleryThumbnail(
      asset: galleryViewModel.assetsList[index],
      size: size,
      onLongPress: () {
        if (!multipleSelection) {
          multipleSelection = true;
          galleryViewModel.selectedAssets.add(galleryViewModel.assetsList[index]);
          galleryProvider.notify();
        }
      },
      onTap: (data) {
        Navigator.push(context, MaterialPageRoute(builder: (context) {
                  return MediaEditorPage(
                      asset: galleryViewModel.assetsList[index],
                      bytes: data);
                }));
      },
    ),
  ),
)

我已添加: ChangeNotifierProvider.value(value: galleryViewModel)包装 GalleryThumbnail .