[How to use] customview 中包含 SliverToBoxAdapter 和 SliverList，怎么观察 SliverToBoxAdapter 比较合适

[chdown]

Platforms

dart

Description

customview 中包含 SliverToBoxAdapter 和 SliverList，怎么观察 SliverToBoxAdapter 比较合适
现在默认应该只会观察 SliverList，SliverGrid，尝试了好几种方式没太理解怎么观察 SliverToBoxAdapter 比较好

My code

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Try do it

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[LinXunFeng]

观察 sliver 需要使用 onObserveViewport

flutter_scrollview_observer/example/lib/features/scene/waterfall_flow_demo/waterfall_flow_page.dart

Lines 74 to 93 in 42968f6

	onObserveViewport: (result) {
	firstChildCtxInViewport = result.firstChild.sliverContext;
	if (firstChildCtxInViewport == grid1Context) {
	debugPrint('current first sliver in viewport - gridView1');
	if (WaterFlowHitType.firstGrid == hitType) return;
	hitType = WaterFlowHitType.firstGrid;
	hitIndex = -1;
	} else if (firstChildCtxInViewport == swipeContext) {
	debugPrint('current first sliver in viewport - swipeView');
	if (WaterFlowHitType.swipe == hitType) return;
	setState(() {
	hitType = WaterFlowHitType.swipe;
	});
	} else if (firstChildCtxInViewport == grid2Context) {
	debugPrint('current first sliver in viewport - gridView2');
	if (WaterFlowHitType.secondGrid == hitType) return;
	hitType = WaterFlowHitType.secondGrid;
	hitIndex = -1;
	}
	},

1. 使用 GlobalKey 或者 SliverObserveContextToBoxAdapter 拿到 sliver 最外层的 ctx，注意，是最外层！
2. 将所有的 sliver 的 ctx 传给 sliverContexts
3. 在 onObserveViewport 回调中可以拿到你需要的观察数据

文章: Flutter - 瀑布流交替播放视频

[chdown]

观察 sliver 需要使用 onObserveViewport

flutter_scrollview_observer/example/lib/features/scene/waterfall_flow_demo/waterfall_flow_page.dart

Lines 74 to 93 in 42968f6

onObserveViewport: (result) {
firstChildCtxInViewport = result.firstChild.sliverContext;
if (firstChildCtxInViewport == grid1Context) {
debugPrint('current first sliver in viewport - gridView1');
if (WaterFlowHitType.firstGrid == hitType) return;
hitType = WaterFlowHitType.firstGrid;
hitIndex = -1;
} else if (firstChildCtxInViewport == swipeContext) {
debugPrint('current first sliver in viewport - swipeView');
if (WaterFlowHitType.swipe == hitType) return;
setState(() {
hitType = WaterFlowHitType.swipe;
});
} else if (firstChildCtxInViewport == grid2Context) {
debugPrint('current first sliver in viewport - gridView2');
if (WaterFlowHitType.secondGrid == hitType) return;
hitType = WaterFlowHitType.secondGrid;
hitIndex = -1;
}
},

1. 使用 GlobalKey 或者 SliverObserveContextToBoxAdapter 拿到 sliver 最外层的 ctx，注意，是最外层！
2. 将所有的 sliver 的 ctx 传给 sliverContexts
3. 在 onObserveViewport 回调中可以拿到你需要的观察数据

文章: Flutter - 瀑布流交替播放视频

感谢