Question

我正在尝试使用Stack小部件和Stack小部件内的三个ListView来快速构建Jackpot游戏，但是它不起作用。当我将ListView放入堆栈时，就会出现错误。我曾尝试先将其包装在Expanded，Container和Flexible小部件中，但是它不起作用。

这是构建支架主体的代码：

Widget _buildBody(GameArguments args) {
    return Container(
        child: Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        _buildJackpot(),
        _buildPuller(),
      ],
    ));
  }

以下是构建累积奖金的代码：

List<Image> left = [
    Image.asset(
      'src/images/hites_logo_trans2.png',
      height: 100,
      width: 200,
    )
  ];

Widget build(BuildContext context) {
    return Container(
      child: Stack(
        children: [
          Container(),
          Image.asset('src/images/jackpot_fome.png'),
          Container(
            child: ListView.builder(
              itemBuilder: (BuildContext context, int index) {
                return left[index];
              },
            ),
          )
        ],
      ),
    );
  }

这是完整的错误日志，我真的不知道发生了什么事：（

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
[38;5;244mThe following assertion was thrown during performResize():[39;49m
Vertical viewport was given unbounded width.

[38;5;244mViewports expand in the cross axis to fill their container and constrain their children to match their extent in the cross axis. In this case, a vertical viewport was given an unlimited amount of horizontal space in which to expand.[39;49m
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;244mWhen the exception was thrown, this was the stack[39;49m
[38;5;244m#0      RenderViewport.performResize.<anonymous closure>[39;49m
 package:flutter/…/rendering/viewport.dart
[38;5;244m#1      RenderViewport.performResize[39;49m
 package:flutter/…/rendering/viewport.dart
[38;5;244m#2      RenderObject.layout[39;49m
 package:flutter/…/rendering/object.dart
[38;5;244m#3      RenderProxyBoxMixin.performLayout[39;49m
 package:flutter/…/rendering/proxy_box.dart
[38;5;244m#4      RenderObject.layout[39;49m
 package:flutter/…/rendering/object.dart
[38;5;244m...[39;49m
[38;5;244mThe following RenderObject was being processed when the exception was fired: RenderViewport#d36b3 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE[39;49m
[38;5;244mRenderObject: RenderViewport#d36b3 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE[39;49m
    [38;5;244mneeds compositing[39;49m
    [38;5;244mparentData: <none> (can use size)[39;49m
    [38;5;244mconstraints: BoxConstraints(0.0<=w<=Infinity, 0.0<=h<=552.9)[39;49m
    [38;5;244msize: MISSING[39;49m
    [38;5;244maxisDirection: down[39;49m
    [38;5;244mcrossAxisDirection: right[39;49m
    [38;5;244moffset: ScrollPositionWithSingleContext#86e2d(offset: 0.0, range: null..null, viewport: null, ScrollableState, AlwaysScrollableScrollPhysics -> ClampingScrollPhysics -> RangeMaintainingScrollPhysics, IdleScrollActivity#0f03e, ScrollDirection.idle)[39;49m
    [38;5;244manchor: 0.0[39;49m
    [38;5;244mcenter child: RenderSliverPadding#b94be NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE[39;49m
        [38;5;244mparentData: paintOffset=Offset(0.0, 0.0)[39;49m
        [38;5;244mconstraints: MISSING[39;49m
        [38;5;244mgeometry: null[39;49m
        [38;5;244mpadding: EdgeInsets(0.0, 24.0, 0.0, 0.0)[39;49m
        [38;5;244mtextDirection: ltr[39;49m
        [38;5;244mchild: RenderSliverList#00bb5 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE[39;49m
            [38;5;244mparentData: paintOffset=Offset(0.0, 0.0)[39;49m
            [38;5;244mconstraints: MISSING[39;49m
            [38;5;244mgeometry: null[39;49m
            [38;5;244mno children current live[39;49m
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderViewport#d36b3 NEEDS-LAYOUT NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderViewport#d36b3 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderIgnorePointer#313f0 relayoutBoundary=up11 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderSemanticsAnnotations#a67f0 relayoutBoundary=up10 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderPointerListener#ec676 relayoutBoundary=up9 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderSemanticsGestureHandler#1df12 relayoutBoundary=up8 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderPointerListener#f871d relayoutBoundary=up7 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: _RenderScrollSemantics#5c527 relayoutBoundary=up6 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderRepaintBoundary#50cc7 relayoutBoundary=up5 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderCustomPaint#7a42d relayoutBoundary=up4 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mListView[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderRepaintBoundary#a7239 relayoutBoundary=up3 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mStack[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m
Reloaded 3 of 581 libraries in 571ms.

[38;5;248m════════ Exception caught by rendering library ═════════════════════════════════[39;49m
RenderBox was not laid out: RenderRepaintBoundary#a7239 relayoutBoundary=up3 NEEDS-PAINT
'package:flutter/src/rendering/box.dart':
Failed assertion: line 1785 pos 12: 'hasSize'
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mStack[39;49m
 lib/pages/GamePage.dart
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m

Answer 1

此代码有很多问题。首先，您必须在Listview.builder中提供itemcount。其次，您需要调整包装它描述的ListView的容器的大小。

Answer 2

有两个主要问题

ListView没有项目计数
您必须将lsitview用Containeror大小的盒子或卡片包装起来以赋予其一定的高度

尝试以下代码：我认为您可能会得到答案

容器（高度：500，宽度：MediaQuery.of（context）.size.width，儿童： ListView.builder（ itemCount：13 itemBuilder ：（上下文，i）{ 返回填充（填充：const EdgeInsets.all（8.0），子级：ListTile（title：Text（“ Try it”），），）; }，），），

堆栈内的ListView.builder无法正常工作

2 个答案: