Flutter Listview可滚动行

Question

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

我使用了大小的盒子,似乎仍然有错误.

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

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

医生总结(查看所有细节,运行扑动医生-v):

[✓] Flutter(Channel beta,v0.4.4,Mac OS X 10.13.1 17B1003,locale en-HK)

[✓] Android工具链 - 针对Android设备开发(Android SDK 26.0.2)

[✓] iOS工具链 - 为iOS设备开发(Xcode 9.2)

[✓] Android Studio(3.1版)

[✓]连接设备(3个可用)

Answer 1

试试这段代码,

您可以使用下面的代码在flutter中实现可滚动的行

对于可滚动列,只需将"Row"更改为"Column"

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

看到这里的输出

Answer 2

尝试设置 ListView 的以下属性

shrinkWrap: true,
physics: ClampingScrollPhysics(), 

对我来说，大多数 Unbound 约束和滚动错误都已解决。

Answer 3

您可以使用Expanded小部件来包装您的listView.扩展的小部件告诉屏幕允许小部件想要占用的空间.

或者你也可以写shrinkWrap:true你的ListView小部件(在很多情况下工作).

Answer 4

水平ListView将垂直扩展以占据其父级的高度.恰好在这种情况下,父亲是一个垂直的ListView,具有无限的高度.你需要约束你内心的高度ListView.

可能最简单的方法是通过一个SizedBox小部件.

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

编辑:

问题实际上是由垂直引起的ListView,因为它是a的孩子Column.原因与上面类似,a ListView将扩展为其父级的高度,并且Column具有无限高度.

此代码段显示症状.

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

这种情况下的解决方案取决于您的设置.你可以再把它包SizedBox起来.您可以将列项目作为您的一部分ListView.或者你也可以改变ListView一个Column.