问题描述
我的代码有问题，我不知道发生了什么，因为没有任何东西亮起。 当我重新加载代码并单击屏幕上的某些内容时，我的终端会显示：
> ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
The following assertion was thrown during performResize():
Vertical viewport was given unbounded height.
Viewports expand in the scrolling direction to fill their container. In this case,a vertical
viewport was given an unlimited amount of vertical space in which to expand. This situation
typically happens when a scrollable widget is nested inside another scrollable widget.
If this widget is always nested in a scrollable widget there is no need to use a viewport because
there will always be enough vertical space for the children. In this case,consider using a Column
instead. Otherwise,consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
the height of the viewport to the sum of the heights of its children.
The relevant error-causing widget was:
ListView
file:///Users/dominikkolber/Desktop/algoTrading/worked_project/lib/widgets/transactions_list.dart:15:25
When the exception was thrown,this was the stack:
#0 RenderViewport.computeDryLayout.<anonymous closure> (package:Flutter/src/rendering/viewport.dart:1365:15)
#1 RenderViewport.computeDryLayout (package:Flutter/src/rendering/viewport.dart:1426:6)
#2 RenderBox.performResize (package:Flutter/src/rendering/Box.dart:2342:12)
#3 RenderObject.layout (package:Flutter/src/rendering/object.dart:1763:9)
#4 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#5 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#6 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#7 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#8 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#9 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#10 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#11 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#12 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#13 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#14 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#15 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#16 RenderConstrainedBox.performlayout (package:Flutter/src/rendering/proxy_Box.dart:279:14)
#17 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#18 ChildLayoutHelper.layoutChild (package:Flutter/src/rendering/layout_helper.dart:54:11)
#19 RenderFlex._computeSizes (package:Flutter/src/rendering/flex.dart:897:45)
#20 RenderFlex.performlayout (package:Flutter/src/rendering/flex.dart:932:32)
#21 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#22 ChildLayoutHelper.layoutChild (package:Flutter/src/rendering/layout_helper.dart:54:11)
#23 RenderFlex._computeSizes (package:Flutter/src/rendering/flex.dart:830:43)
#24 RenderFlex.performlayout (package:Flutter/src/rendering/flex.dart:932:32)
#25 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#26 _RenderSingleChildViewport.performlayout (package:Flutter/src/widgets/single_child_scroll_view.dart:558:14)
#27 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#28 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#29 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#30 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#31 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#32 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#33 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#34 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#35 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#36 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#37 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#38 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#39 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#40 MultiChildLayoutDelegate.layoutChild (package:Flutter/src/rendering/custom_layout.dart:171:12)
#41 _ScaffoldLayout.performlayout (package:Flutter/src/material/scaffold.dart:925:7)
#42 MultiChildLayoutDelegate._callPerformlayout (package:Flutter/src/rendering/custom_layout.dart:243:7)
#43 RenderCustomMultiChildLayoutBox.performlayout (package:Flutter/src/rendering/custom_layout.dart:407:14)
#44 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#45 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#46 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#47 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#48 _RenderCustomClip.performlayout (package:Flutter/src/rendering/proxy_Box.dart:1371:11)
#49 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#50 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#51 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#52 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#53 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#54 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#55 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#56 ChildLayoutHelper.layoutChild (package:Flutter/src/rendering/layout_helper.dart:54:11)
#57 RenderStack._computeSize (package:Flutter/src/rendering/stack.dart:570:43)
#58 RenderStack.performlayout (package:Flutter/src/rendering/stack.dart:597:12)
#59 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#60 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#61 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#62 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#63 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#64 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#65 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#66 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#67 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#68 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#69 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#70 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#71 RenderOffstage.performlayout (package:Flutter/src/rendering/proxy_Box.dart:3362:13)
#72 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#73 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#74 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#75 _RenderTheatre.performlayout (package:Flutter/src/widgets/overlay.dart:743:15)
#76 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#77 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#78 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#79 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#80 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#81 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#82 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#83 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#84 RenderCustomPaint.performlayout (package:Flutter/src/rendering/custom_paint.dart:546:11)
#85 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#86 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#87 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#88 RenderProxyBoxMixin.performlayout (package:Flutter/src/rendering/proxy_Box.dart:118:14)
#89 RenderObject.layout (package:Flutter/src/rendering/object.dart:1784:7)
#90 RenderView.performlayout (package:Flutter/src/rendering/view.dart:153:14)
#91 RenderObject._layoutWithoutResize (package:Flutter/src/rendering/object.dart:1641:7)
#92 PipelineOwner.flushLayout (package:Flutter/src/rendering/object.dart:884:18)
#93 RendererBinding.drawFrame (package:Flutter/src/rendering/binding.dart:453:19)
#94 WidgetsBinding.drawFrame (package:Flutter/src/widgets/binding.dart:874:13)
#95 RendererBinding._handlePersistentFrameCallback (package:Flutter/src/rendering/binding.dart:319:5)
#96 SchedulerBinding._invokeFrameCallback (package:Flutter/src/scheduler/binding.dart:1144:15)
#97 SchedulerBinding.handleDrawFrame (package:Flutter/src/scheduler/binding.dart:1082:9)
#98 SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:Flutter/src/scheduler/binding.dart:865:7)
(elided 11 frames from class _RawReceivePortImpl,class _Timer,dart:async,and dart:async-patch)
The following RenderObject was being processed when the exception was fired: RenderViewport#cbc71 NEEDS-LAYOUT
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE:
needs compositing
creator: Viewport ← IgnorePointer-[GlobalKey#28017] ← Semantics ← Listener ← _GestureSemantics ←
RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#e8dad] ← Listener ← _ScrollableScope
← _ScrollSemantics-[GlobalKey#d4bfb] ← Scrollable ← ListView ← ConstrainedBox ← ⋯
parentData: <none> (can use size)
constraints: BoxConstraints(w=300.0,0.0<=h<=Infinity)
size: MISSING
axisDirection: down
crossAxisDirection: right
offset: ScrollPositionWithSingleContext#a246f(offset: 0.0,range: null..null,viewport: null,ScrollableState,AlwaysScrollableScrollPhysics -> BouncingScrollPhysics ->
RangeMaintainingScrollPhysics,IdleScrollActivity#b67a4,ScrollDirection.idle)
anchor: 0.0
This RenderObject had the following descendants (showing up to depth 5):
center child: RenderSliverPadding#ab96d NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
child: RenderSliverList#474d3 NEEDS-LAYOUT NEEDS-PAINT
════════════════════════════════════════════════════════════════════════════════════════════════════
Another exception was thrown: RenderBox was not laid out: RenderViewport#cbc71 NEEDS-LAYOUT NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderViewport#cbc71 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#14767 relayoutBoundary=up16 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#8657d relayoutBoundary=up15
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderPointerListener#b5a18 relayoutBoundary=up14 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#fffbd relayoutBoundary=up13
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderPointerListener#12b1c relayoutBoundary=up12 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: _RenderScrollSemantics#59657 relayoutBoundary=up11 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderConstrainedBox#69ea6 relayoutBoundary=up10 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderFlex#0e0b0 relayoutBoundary=up9 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderFlex#a112f relayoutBoundary=up8 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: _RenderSingleChildViewport#45682 relayoutBoundary=up7
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#8bbd3 relayoutBoundary=up6 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#617d0 relayoutBoundary=up5
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderPointerListener#dffcd relayoutBoundary=up4 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#66524 relayoutBoundary=up3
NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: RenderPointerListener#5238d relayoutBoundary=up2 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: _RenderScrollSemantics#01cd6 relayoutBoundary=up1 NEEDS-PAINT
NEEDS-COMPOSITING-BITS-UPDATE
Another exception was thrown: RenderBox was not laid out: _RenderSingleChildViewport#45682 relayoutBoundary=up7
NEEDS-PAINT
Another exception was thrown: Null check operator used on a null value
Another exception was thrown: Bad state: Future already completed
[VERBOSE-2:ui_dart_state.cc(186)] Unhandled Exception: 'package:Flutter/src/rendering/Box.dart': Failed assertion: line 1940 pos 12: 'hasSize': RenderBox was not laid out: RenderPointerListener#14f8e NEEDS-LAYOUT NEEDS-PAINT
#0 _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:46:39)
#1 _AssertionError._throwNew (dart:core-patch/errors_patch.dart:36:5)
#2 RenderBox.size (package:Flutter/src/rendering/Box.dart:1940:12)
#3 RenderProxyBoxWithHitTestBehavior.hitTest (package:Flutter/src/rendering/proxy_Box.dart:179:9)
#4 RenderBoxContainerDefaultsMixin.defaultHitTestChildren.<anonymous closure> (package:Flutter/src/rendering/Box.dart:2785:25)
#5 BoxHitTestResult.addWithPaintOffset (package:Flutter/src/rendering/Box.dart:787:31)
#6 RenderBoxContainerDefaultsMixin.defaultHitTestChildren (package:Flutter/src/rendering/Box.dart:2780:33)
#7 RenderCustomMultiChildLayoutBox.hitTestChildren (package:Flutter/src/rendering/custom_layout.dart:417:12)
#8 Rend<…>
[VERBOSE-2:ui_dart_state.cc(186)] Unhandled Exception: 'package:Flutter/src/rendering/Box.dart': Failed assertion: line 1940 pos 12: 'hasSize': RenderBox was not laid out: RenderPointerListener#14f8e NEEDS-LAYOUT NEEDS-PAINT
#0 _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:46:39)
#1 _AssertionError._throwNew (dart:core-patch/errors_patch.dart:36:5)
#2 RenderBox.size (package:Flutter/src/rendering/Box.dart:1940:12)
#3 RenderProxyBoxWithHitTestBehavior.hitTest (package:Flutter/src/rendering/proxy_Box.dart:179:9)
#4 RenderBoxContainerDefaultsMixin.defaultHitTestChildren.<anonymous closure> (package:Flutter/src/rendering/Box.dart:2785:25)
#5 BoxHitTestResult.addWithPaintOffset (package:Flutter/src/rendering/Box.dart:787:31)
#6 RenderBoxContainerDefaultsMixin.defaultHitTestChildren (package:Flutter/src/rendering/Box.dart:2780:33)
#7 RenderCustomMultiChildLayoutBox.hitTestChildren (package:Flutter/src/rendering/custom_layout.dart:417:12)
#8 Rend<…>
我真的不知道我在看教程时有什么问题，如果有人想帮忙，下面是我的代码
https://gist.github.com/agentkolby/313a65939eb4a8e0a136f5fa7bc36925
解决方法
请在下面尝试。更改 user_transactions.dart 中的代码
Widget build(BuildContext context) {
return Scaffold(
body: Column(
children: <Widget>[
NewTransaction(_addNewTransaction),TransactionList(_userTransactions),],),);
}
您不能在 Expanded 中使用 Column。