Flutter 颤振列表视图可滚动行 ListView( 儿童：[ 新尺寸盒子( 高度：100.0， 子：ListView( 滚动方向：轴水平， 儿童：[ 新文本（“hi”）， 新文本（“hi”）， 新文本（“hi”）， ], ), ), ], )

我用了这个大小的盒子，似乎还是有错误

这是我的小部件树： SingleChildScrollView->Column->children

ListView(
  children: [
    new SizedBox(
      height: 100.0,
      child: ListView(
        scrollDirection: Axis.horizontal,
        children: <Widget>[
          new Text("hi"),
          new Text("hi"),
          new Text("hi"),
        ],
      ),
    ),
  ],
)
    

正在执行热重新加载。。。颤振：══╡ 呈现库捕获到异常╞═════════════════════════════════════════════════════════ 颤振：在performResize（）期间抛出了以下断言：颤振：垂直视口被赋予了无限高。颤振：视口沿滚动方向展开以填充其容器。在这种情况下，垂直颤振：视口被赋予无限的垂直空间以进行展开。这种情况：通常发生在一个可滚动小部件嵌套在另一个可滚动小部件中时。颤振：如果此小部件始终嵌套在可滚动小部件中，则无需使用视口，因为颤振：始终有足够的垂直空间供孩子们使用。在这种情况下，考虑使用柱颤振。否则，考虑使用“收缩包”属性（或收缩包装视图）来调整颤动：视口的高度与它的孩子的高度之和。颤振：颤振：抛出异常时，这是堆栈：颤振：#0 RenderViewport.performResize。（包：颤振/src/rendering/viewport.dart:944:15）颤振：
#1 RenderViewport.performResize（包：flatter/src/rendering/viewport.dart:997:6）flatter:#2 RenderObject.layout（包：flatter/src/rendering/object.dart:1555:9）flatter:#3
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#4 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#5
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#6 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#7
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#8 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#9
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#10 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#11
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：flatter/src/rendering/proxy_box.dart:109:13）颤振：#12 RenderObject.layout（包：flatter/src/rendering/object.dart:1570:7）颤振：#13 RenderFlex.performLayout（包：flatter/src/rendering/flex.dart:738:15）颤振：#14 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#15 RenderPadding.performLayout（包：颤振/src/rendering/shift#box.dart:199:11）颤振：#16 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#17#rendersingle.performLayout（包：flatter/src/widgets/single_child_scroll_view.dart:479:13）flatter:#18 RenderObject.layout（包：flatter/src/rendering/object.dart:1570:7）flatter:#19
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#20 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#21
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#22 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#23
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#24 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#25
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#26 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#27
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（软件包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#28 RenderObject.layout（软件包：颤振/src/rendering/object.dart:1570:7）颤振：#29 RenderPositionedBox.performLayout（软件包：颤振/src/rendering/Shift#box.dart:381:13）颤振：#30 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#31 MultiChildLayoutDelegate.layoutChild（包：颤振/src/rendering/custom#layout.dart:141:11）颤振：#32
_scaffolldlayout.performLayout（包：flatter/src/material/scaffold.dart:399:7）flatter:#33 multichildlayout代表._调用performLayout（包：flatter/src/rendering/custom_layout.dart:211:7）flatter:#34 rendercastommmultichildlayout.performLayout（包：flatter/src/rendering/custom355:14）颤振：35 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：36
_RenderProxy box&RenderBox&RenderObjectWithChildMixin&RenderProxy box Mixin.performLayout（包：颤振/src/rendering/proxy_box.dart:109:13）颤振：#37 RenderObject.layout（包：颤振/src/rendering/object.dart:1570:7）颤振：#38
_RenderProxy Box&RenderBox&RenderObjectWithChildMixin&RenderProxy Box Mixin.performLayout（包
Performing hot reload... flutter: ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════ flutter: The following assertion was thrown during performResize(): flutter: Vertical viewport was given unbounded height. flutter: Viewports expand in the scrolling direction to fill their container.In this case, a vertical flutter: viewport was given an unlimited amount of vertical space in which to expand. This situation flutter: typically happens when a scrollable widget is nested inside another scrollable widget. flutter: If this widget is always nested in a scrollable widget there is no need to use a viewport because flutter: there will always be enough vertical space for the children. In this case, consider using a Column flutter: instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size flutter: the height of the viewport to the sum of the heights of its children. flutter: flutter: When the exception was thrown, this was the stack: flutter: #0      RenderViewport.performResize.<anonymous closure> (package:flutter/src/rendering/viewport.dart:944:15) flutter:
#1      RenderViewport.performResize (package:flutter/src/rendering/viewport.dart:997:6) flutter: #2      RenderObject.layout (package:flutter/src/rendering/object.dart:1555:9) flutter: #3     
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #4      RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #5     
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #6      RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #7     
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #8      RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #9     
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #10     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #11    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #12     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #13     RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:738:15) flutter: #14     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #15     RenderPadding.performLayout (package:flutter/src/rendering/shifted_box.dart:199:11) flutter: #16   RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #17     _RenderSingleChildViewport.performLayout (package:flutter/src/widgets/single_child_scroll_view.dart:479:13) flutter: #18     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #19    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #20     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #21    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #22     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #23    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #24     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #25    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #26     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #27    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #28     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #29     RenderPositionedBox.performLayout (package:flutter/src/rendering/shifted_box.dart:381:13) flutter: #30   RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #31     MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:141:11) flutter: #32
_ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:399:7) flutter: #33     MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:211:7) flutter: #34  RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:355:14) flutter: #35 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #36    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #37     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #38    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #39    
_RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1143:11) flutter: #40    RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #41    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #42     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #43    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #44     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #45    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #46     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #47     RenderStack.performLayout (package:flutter/src/rendering/stack.dart:520:15) flutter: #48     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #49    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #50     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #51    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #52     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #53    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #54     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #55    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #56     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #57    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #58     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #59    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #60     RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:2809:13) flutter: #61    RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #62     RenderStack.performLayout (package:flutter/src/rendering/stack.dart:520:15) flutter: #63     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #64    
__RenderTheatre&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #65     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #66    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #67     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #68    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #69     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #70    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #71     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #72    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #73     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #74    
_RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13) flutter: #75     RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7) flutter: #76     RenderView.performLayout (package:flutter/src/rendering/view.dart:125:13) flutter: #77     RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1445:7) flutter: #78     PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:709:18) flutter: #79    
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:270:19) flutter: #80    
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:627:13) flutter: #81    
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5) flutter: #82    
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15) flutter: #83    
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9) flutter: #84    
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:751:7) flutter:
#86     _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19) flutter: #87    
_Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5) flutter: #88     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:165:12) flutter: (elided one frame from package dart:async) flutter: flutter: The following RenderObject was being processed when the exception was fired: flutter:   RenderViewport#c5015 NEEDS-LAYOUT NEEDS-PAINT flutter:   creator: Viewport ← _ScrollableScope ← IgnorePointer-[GlobalKey#58446] ← Semantics ← Listener ← flutter:   _GestureSemantics ← RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#efcf9] ← flutter:   _ExcludableScrollSemantics-[GlobalKey#1ff3b] ← Scrollable ← ListView ← Column ← Padding ← ⋯ flutter:   parentData: <none> (can use size) flutter:   constraints: BoxConstraints(0.0<=w<=335.0,
0.0<=h<=Infinity) flutter:   size: MISSING flutter:   axisDirection: down flutter:   crossAxisDirection: right flutter:   offset: ScrollPositionWithSingleContext#05c53(offset: 0.0, range: null..null, viewport: null, flutter:   ScrollableState, AlwaysScrollableScrollPhysics -> BouncingScrollPhysics, IdleScrollActivity#31dab, flutter:   ScrollDirection.idle) flutter:   anchor: 0.0 flutter: This RenderObject had the following descendants (showing up to depth 5): flutter:   RenderSliverPadding#912f7 NEEDS-LAYOUT NEEDS-PAINT flutter:     RenderSliverList#41182 NEEDS-LAYOUT NEEDS-PAINT flutter:       RenderRepaintBoundary#8a6de NEEDS-LAYOUT NEEDS-PAINT flutter:         RenderConstrainedBox#4bfc3 NEEDS-LAYOUT NEEDS-PAINT flutter:          
_RenderExcludableScrollSemantics#0976e NEEDS-LAYOUT NEEDS-PAINT flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════ flutter: Another exception was thrown: RenderBox was not laid out: RenderViewport#c5015 NEEDS-LAYOUT NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderViewport#c5015 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#a987c relayoutBoundary=up14 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#9bd09 relayoutBoundary=up13 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderPointerListener#12af7 relayoutBoundary=up12 NEEDS-PAINT Reloaded 1 of 493 libraries in 603ms. flutter: Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#27e1a relayoutBoundary=up11 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out:
_RenderExcludableScrollSemantics#85fc5 relayoutBoundary=up10 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderFlex#19bee relayoutBoundary=up9 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderPadding#e802a relayoutBoundary=up8 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out:
_RenderSingleChildViewport#5d1aa relayoutBoundary=up7 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#f73b8 relayoutBoundary=up6 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#610b2 relayoutBoundary=up5 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderPointerListener#cbdf9 relayoutBoundary=up4 NEEDS-PAINT flutter: Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#37577 relayoutBoundary=up3 NEEDS-PAINT flutter: Another exception was thrown: 'package:flutter/src/rendering/shifted_box.dart': Failed assertion: line 310 pos 12: 'child.hasSize': is not true. flutter: Another exception was thrown: RenderBox was not laid out:
_RenderSingleChildViewport#5d1aa relayoutBoundary=up7 NEEDS-P

ListView(
  children: [
    SizedBox(
      height: 300.0,
      child: ListView(scrollDirection: Axis.horizontal, ...),
    ),
  ],
)

Column(
  children: <Widget>[
    ListView(children: [Text("hi"), Text("hi"), Text("hi")]),
  ],
)

new Expanded (
    child: new ListView (
                      .....
    )
)

new Listview(
children: <Widget>[
    new SizedBox(
        height:100.0,
        child: new Row(
            children: <Widget>[
                new Text("hi"),
                new Text("hi"),
                new Text("hi"),
            ]
        )
    )
]

SingleChildScrollView(
  scrollDirection: Axis.horizontal,
  child: Row(
   children: <Widget>[
     Text('hi'),
     Text('hi'),
     Text('hi'),
   ]
  )
)

import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {


  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(widget.title),
      ),
      body: 
        _listView(),

    );
  }

  ListView _listView() {
    return new ListView(
      children: [
        new SizedBox(
          height: 100.0,
          child: ListView(
            scrollDirection: Axis.horizontal,
            children: <Widget>[
            new Text("hi"),
            new Text("hi"),
            new Text("hi"),
            ],
          ),
        ),
      ],
    );

  }

}

 child: SingleChildScrollView(
    scrollDirection: Axis.horizontal,
    child: Row(
      children: <Widget>[
        buildCard(context),
        buildCard(context),
        buildCard(context),
      ],
    ),
  ),

Container(
    height: 100.0,
    child: ListView(
        scrollDirection: Axis.horizontal,
        children: <Widget>[
            new Text("hi"),
            new Text("hi"),
            new Text("hi"),
        ]
    ),
),

  return Scaffold(
  body: ListView.builder(
    scrollDirection: Axis.vertical,
    itemBuilder: (BuildContext context, int index) {
      return Container(
        height: 200,
        margin: EdgeInsets.all(20),
        child: ListView.builder(
          scrollDirection: Axis.horizontal,
          itemCount: 20,
          itemBuilder: (BuildContext context, int index) {
            return Container(
              color: Colors.grey,
              width: 100,
              height: 100,
              margin: EdgeInsets.all(20),
            );
          },
        ),
      );
    },
  ),
);

shrinkWrap: true,
physics: ClampingScrollPhysics(),