错误 ExpansionTile 不工作或堆栈（Flutter）

Question

I'm trying to solve an issue; however, it still not working and I'm getting the same error. I hope someone could give me an answer, thanks.

Code

  child: FirestoreListView<MainCategory>(
                    scrollDirection: Axis.horizontal,
                    query: mainCategoryCollection(widget.selectedCat),
                    itemBuilder: (context, snapshot) {
                      MainCategory mainCategory = snapshot.data();
                      return ExpansionTile(
                          title: Text(mainCategory.mainCategory!),
                        children: [
                          SubCategoryWidget(
                            selectedSubCat: mainCategory.mainCategory,
                          ),
                        
                        ],
                        );
                    },
                  ),
);

} } `

======== Exception caught by rendering library ===================================================== The following assertion was thrown during performLayout(): 'package:flutter/src/rendering/object.dart': Failed assertion: line 1840 pos 12: ':_debugDoingThisLayout'. is not true.

The relevant error-causing widget was: ExpansionTile ExpansionTile:file:///C:/Users/faruq/AndroidStudioProjects/foodcourtapp/lib/category/main_category_widget.dart:26:34 When the exception was thrown, this was the stack:
#2 RenderObject.layout (package:flutter/src/rendering/object.dart:1840:12)

#3 RenderPositionedBox.performLayout (package:flutter/src/rendering/shifted_box.dart:437:14)

#4 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#5 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:116:14)

#6 _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1376:11)

#7 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#8 ChildLayoutHelper.layoutChild (package:flutter/src/rendering /layout_helper.dart:56:11)

#9 RenderFlex._computeSizes (package:flutter/src/rendering/flex.dart:829:43)

#10 RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:931:32)

#11 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#12 RenderPadding.performLayout (package:flutter/src/rendering/shifted_box.dart:233:12)

#13 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#14 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering /proxy_box.dart:116:14)

#15 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#16 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:116:14)

#17 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#18 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:116:14)

#19 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#20 RenderSliverList.performLayout (package:flutter/src/rendering/sliver_list.dart:213:28)

#21 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#22 RenderSliverEdgeInsetsPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:137:12)

#23 RenderSliverPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:371:11)

#24 RenderObject.layout (package:flutter/src/rendering/object.dart:1915:7)

#25 RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:510:13)

#26 RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1580:12)

#27 RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1489:20)

#28 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1757:7)

#29 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:887:18)

#30 RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:504:19)

#31 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:892:13)

#32 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:370:5)

#33 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1146:15)

#34 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1083:9)

#35 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:997:5)

#39 _invoke (dart:ui/hooks.dart:151:10)

#40 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:308:5)

#41 _drawFrame (dart:ui/hooks.dart:115:31)

(elided 5 frames from class _AssertionError and dart:async)

The following RenderObject was being processed when the exception was fired:

RenderPositionedBox#62a81 relayoutBoundary=up9 NEEDS-LAYOUT NEEDS-COMPOSITING-BITS-UPDATE

... parentData: (can use size)

... constraints: BoxConstraints(0.0<=w<=312.7, 0.0<=h<=Infinity)

... size: Size(312.7, 0.0)

... alignment: Alignment.center

... textDirection: ltr

... widthFactor: expand

... heightFactor: 1.0

RenderObject: RenderPositionedBox#62a81 relayoutBoundary=up9 NEEDS-LAYOUT NEEDS- COMPOSITING-BITS-UPDATE

parentData: (can use size)

constraints: BoxConstraints(0.0<=w<=312.7, 0.0<=h<=Infinity)

size: Size(312.7, 0.0)

alignment: Alignment.center

textDirection: ltr

widthFactor: expand

heightFactor: 1.0

... child: RenderOffstage#06e2c relayoutBoundary=up10 NEEDS-LAYOUT NEEDS-COMPOSITING-BITS- UPDATE

... parentData: offset=Offset(0.0, 0.0) (can use size)

... constraints: BoxConstraints(0.0<=w<=312.7, 0.0<=h<=Infinity)

... size: MISSING

... offstage: false

... child: RenderPadding#fba79 relayoutBoundary=up11 NEEDS-LAYOUT NEEDS-COMPOSITING- BITS-UPDATE

... parentData: (can use size)

... constraints: BoxConstraints(0.0<=w<=312.7, 0.0<=h<=Infinity)

... size: MISSING

... padding: EdgeInsets.zero

... textDirection: ltr

... child: RenderFlex#d4c2f relayoutBoundary=up12 NEEDS-LAYOUT NEEDS-COMPOSITING-BITS- UPDATE

... parentData: offset=Offset(0.0, 0.0) (can use size)

... constraints: BoxConstraints(0.0<=w<=312.7, 0.0<=h<=Infinity)

... size: MISSING

... direction: vertical

... mainAxisAlignment: start

... mainAxisSize: max

... crossAxisAlignment: center

... verticalDirection: down

... child 1: RenderRepaintBoundary#79e1d NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-

BITS-UPDATE

... needs compositing

... parentData: offset=Offset(0.0, 0.0); flex=1; fit=FlexFit.tight

... constraints: MISSING

... size: MISSING

... usefulness ratio: no metrics collected yet (never painted)

... child 2: RenderConstrainedBox#42f8a NEEDS-LAYOUT NEEDS-PAINT

... parentData: offset=Offset(0.0, 0.0); flex=null; fit=null

... constraints: MISSING

... size: MISSING

... additionalConstraints: BoxConstraints(0.0<=w<=Infinity, h=0.0)

Answer 1

Wrap FirestoreListView with SizedBox and add a height to the later; if FirestoreListView 's parent is a box ( SizedBox , Container , ConstrainedBox ... ), add height to the parent instead.