当我导航到新页面时，我从flutter包sliver.dart中获得了此异常。
所有这些都工作正常，但是后来我尝试向其添加多个功能，例如连接sqlite数据库，我认为这就是问题所在，因此我尝试通过删除所有其他功能来返回到应用的最后工作状态码。但不幸的是，它仍然给我这个错误。即使您在下面查看我的前端代码，现在也没有什么特别的，它只是显示对象中已有的数据。
尝试完全重新安装该应用程序，但仍然没有解决方案。
Running "flutter packages get" in heron... 1.5s
Launching lib\main.dart on Android SDK built for x86 in debug mode...
Built build\app\outputs\apk\debug\app-debug.apk.
D/ (23206): HostConnection::get() New Host Connection established 0xa4b249c0, tid 23228
D/EGL_emulation(23206): eglMakeCurrent: 0xa6594cc0: ver 3 0 (tinfo 0x94a360d0)
I/flutter (23206): TV GET Requested
I/flutter (23206): Movie GET Requested
I/flutter (23206): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (23206): The following assertion was thrown during performLayout():
I/flutter (23206): 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 553 pos 12: 'child != null': is
I/flutter (23206): not true.
I/flutter (23206):
I/flutter (23206): Either the assertion indicates an error in the framework itself, or we should provide substantially
I/flutter (23206): more information in this error message to help you determine and fix the underlying cause.
I/flutter (23206): In either case, please report this assertion by filing a bug on GitHub:
I/flutter (23206): https://github.com/flutter/flutter/issues/new?template=BUG.md
I/flutter (23206):
I/flutter (23206): When the exception was thrown, this was the stack:
I/flutter (23206): #2 SliverChildListDelegate.build
I/flutter (23206): #3 SliverMultiBoxAdaptorElement._build.<anonymous closure>
I/flutter (23206): #4 _HashMap.putIfAbsent (dart:collection/runtime/libcollection_patch.dart:137:29)
I/flutter (23206): #5 SliverMultiBoxAdaptorElement._build
I/flutter (23206): #6 SliverMultiBoxAdaptorElement.createChild.<anonymous closure>
I/flutter (23206): #7 BuildOwner.buildScope
I/flutter (23206): #8 SliverMultiBoxAdaptorElement.createChild
I/flutter (23206): #9 RenderSliverMultiBoxAdaptor._createOrObtainChild.<anonymous closure>
I/flutter (23206): #10 RenderObject.invokeLayoutCallback.<anonymous closure>
I/flutter (23206): #11 PipelineOwner._enableMutationsToDirtySubtrees
I/flutter (23206): #12 RenderObject.invokeLayoutCallback
I/flutter (23206): #13 RenderSliverMultiBoxAdaptor._createOrObtainChild
I/flutter (23206): #14 RenderSliverMultiBoxAdaptor.insertAndLayoutChild
I/flutter (23206): #15 RenderSliverList.performLayout.advance
I/flutter (23206): #16 RenderSliverList.performLayout
I/flutter (23206): #17 RenderObject.layout
I/flutter (23206): #18 RenderSliverPadding.performLayout
I/flutter (23206): #19 RenderObject.layout
I/flutter (23206): #20 RenderViewportBase.layoutChildSequence
I/flutter (23206): #21 RenderViewport._attemptLayout
I/flutter (23206): #22 RenderViewport.performLayout
I/flutter (23206): #23 RenderObject.layout
I/flutter (23206): #24 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #25 RenderObject.layout
I/flutter (23206): #26 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #27 RenderObject.layout
I/flutter (23206): #28 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #29 RenderObject.layout
I/flutter (23206): #30 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #31 RenderObject.layout
I/flutter (23206): #32 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #33 RenderObject.layout
I/flutter (23206): #34 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #35 RenderObject.layout
I/flutter (23206): #36 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #37 RenderObject.layout
I/flutter (23206): #38 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #39 RenderObject.layout
I/flutter (23206): #40 RenderPadding.performLayout
I/flutter (23206): #41 RenderObject.layout
I/flutter (23206): #42 MultiChildLayoutDelegate.layoutChild
I/flutter (23206): #43 _ScaffoldLayout.performLayout
I/flutter (23206): #44 MultiChildLayoutDelegate._callPerformLayout
I/flutter (23206): #45 RenderCustomMultiChildLayoutBox.performLayout
I/flutter (23206): #46 RenderObject.layout
I/flutter (23206): #47 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #48 RenderObject.layout
I/flutter (23206): #49 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #50 _RenderCustomClip.performLayout
I/flutter (23206): #51 RenderObject.layout
I/flutter (23206): #52 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #53 RenderObject.layout
I/flutter (23206): #54 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #55 RenderObject.layout
I/flutter (23206): #56 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #57 RenderObject.layout
I/flutter (23206): #58 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #59 RenderObject.layout
I/flutter (23206): #60 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #61 RenderObject.layout
I/flutter (23206): #62 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #63 RenderObject.layout
I/flutter (23206): #64 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout
I/flutter (23206): #65 RenderObject.layout
I/flutter (23206): #66 RenderOffstage.performLayout
I/flutter (23206): #67 RenderObject.layout
I/flutter (23206): #68 RenderStack.performLayout
I/flutter (23206): #69 RenderObject._layoutWithoutResize
I/flutter (23206): #70 PipelineOwner.flushLayout
I/flutter (23206): #71 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame
I/flutter (23206): #72 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame
I/flutter (23206): #73 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback
I/flutter (23206): #74 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback
I/flutter (23206): #75 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame
I/flutter (23206): #76 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame
I/flutter (23206): #80 _invoke (dart:ui/hooks.dart:209:10)
I/flutter (23206): #81 _drawFrame (dart:ui/hooks.dart:168:3)
I/flutter (23206): (elided 5 frames from class _AssertionError and package dart:async)
I/flutter (23206):
I/flutter (23206): The following RenderObject was being processed when the exception was fired:
I/flutter (23206): RenderSliverList#19980 relayoutBoundary=up2 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (23206): creator: SliverList ← MediaQuery ← SliverPadding ← Viewport ← IgnorePointer-[GlobalKey#7290e] ←
I/flutter (23206): Semantics ← Listener ← _GestureSemantics ←
I/flutter (23206): RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#9ea0f] ← _ScrollableScope ←
I/flutter (23206): _ScrollSemantics-[GlobalKey#aa43f] ← RepaintBoundary ← ⋯
I/flutter (23206): parentData: paintOffset=Offset(0.0, 0.0) (can use size)
I/flutter (23206): constraints: SliverConstraints(AxisDirection.down, GrowthDirection.forward, ScrollDirection.idle,
I/flutter (23206): scrollOffset: 0.0, remainingPaintExtent: 598.4, crossAxisExtent: 381.4, crossAxisDirection:
I/flutter (23206): AxisDirection.right, viewportMainAxisExtent: 598.4, remainingCacheExtent: 848.4 cacheOrigin: 0.0 )
I/flutter (23206): geometry: null
I/flutter (23206): currently live children: 0 to 2
I/flutter (23206): This RenderObject had the following descendants (showing up to depth 5):
I/flutter (23206): RenderIndexedSemantics#6d89b relayoutBoundary=up3 NEEDS-PAINT
I/flutter (23206): RenderRepaintBoundary#41a15 relayoutBoundary=up4 NEEDS-PAINT
I/flutter (23206): RenderConstrainedBox#f6331 relayoutBoundary=up5 NEEDS-PAINT
I/flutter (23206): RenderStack#1d492 NEEDS-PAINT
I/flutter (23206): RenderSemanticsAnnotations#dee5b relayoutBoundary=up1 NEEDS-PAINT
I/flutter (23206): RenderSemanticsAnnotations#75402 NEEDS-PAINT
I/flutter (23206): RenderConstrainedBox#553a7 relayoutBoundary=up1 NEEDS-PAINT
I/flutter (23206): RenderIndexedSemantics#dbd86 relayoutBoundary=up3 NEEDS-PAINT
I/flutter (23206): RenderRepaintBoundary#d9292 relayoutBoundary=up4 NEEDS-PAINT
I/flutter (23206): RenderDecoratedBox#fdc4c relayoutBoundary=up5 NEEDS-PAINT
I/flutter (23206): RenderSemanticsGestureHandler#fac22 relayoutBoundary=up6 NEEDS-PAINT
I/flutter (23206): RenderPointerListener#bca58 relayoutBoundary=up7 NEEDS-PAINT
I/flutter (23206): RenderIndexedSemantics#dc7c8 relayoutBoundary=up3 NEEDS-PAINT
I/flutter (23206): RenderRepaintBoundary#f0361 relayoutBoundary=up4 NEEDS-PAINT
I/flutter (23206): RenderSemanticsGestureHandler#29897 relayoutBoundary=up5 NEEDS-PAINT
I/flutter (23206): RenderPointerListener#e3417 relayoutBoundary=up6 NEEDS-PAINT
I/flutter (23206): RenderSemanticsAnnotations#69a6f relayoutBoundary=up7 NEEDS-PAINT
I/flutter (23206): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (23206): Another exception was thrown: NoSuchMethodError: The getter 'scrollOffsetCorrection' was called on null.
I/flutter (23206): Another exception was thrown: NoSuchMethodError: The method 'debugAssertIsValid' was called on null.
I/flutter (23206): Another exception was thrown: NoSuchMethodError: The getter 'visible' was called on null.
我已将代码分为两页
前端-https://gist.github.com/purplecandy/54234b2080f27b43075ef289489ecf5b
功能-https://gist.github.com/purplecandy/8d7a8cb0e3e001d6517ddc21dde72256
pubspec-https://gist.github.com/purplecandy/06be5d9a521239052a25cbe6e042471b
任何人都可以给我一些见解导致此问题的原因吗？我哪里错了？或者只是向我解释错误
答案 0 :(得分：0)
根据日志，Widget 的预期 child 似乎为空。如果您仍然遇到问题，分享导致错误的行的代码片段应该有助于我们理解问题。