颤动 - 在同一页面上添加卡片和文本列表后出现异常

Question

我想显示文本（或其他类型的内容）和卡列表。我只能显示卡列表，但如果我添加另一个类，它会抛出异常。

仅限卡片列表的代码（可行）：

class CardPageState extends State<CardPage> {

  //DeckCard is a class which contains title, description, etc
  final decks = <DeckCard>[];

  CardPageState(data){
    decks.addAll(data);
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      child: buildCardPage(),
    );
  }

  Widget buildCardPage() {
    return new Container(
          child: new ListView.builder(
                itemCount: decks.length,
                itemBuilder: /*1*/ (context, i) {
                  return _buildRow(decks[i]);
                })


    );
  }

  Widget _buildRow(DeckCard deckCard) {

    return new Card(
        child: Text(deckCard.getTitle(), style: TextStyle(fontWeight: FontWeight.bold,fontSize: 20, color:Colors.black),)
    );
  }
}

从具有正文的主页调用CardPage：

body: new Container(
        child: new FutureBuilder<DeckCardResponse>(
        future: fetchDecksFromFirebase(),
        builder: (context, snapshot) {

            if (snapshot.hasData) {
                return new CardPage(snapshot.data.getDecks());

            }
            else if (snapshot.hasError) {
                return new MessageError(499);

            }
            return new CircularProgressIndicator(strokeWidth: 5.0);
        }),
    )

当我尝试添加其他内容时，它会抛出异常：

Widget buildCardPage() {
    return new Container(
          child:
          new Column(
            children:[
              new Text("hello", style: TextStyle(fontWeight: FontWeight.bold,fontSize: 20, color:Colors.black),),
              new Container(
                child: new ListView.builder(
                itemCount: decks.length,
                itemBuilder: /*1*/ (context, i) {
                  return _buildRow(decks[i]);
                })

              ),
            ]
          ),
    );

任何的想法？我尝试只使用没有前一个Container的列，但是，我有相同的例外。

I/flutter (18134): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (18134): The following assertion was thrown during performResize():
I/flutter (18134): Vertical viewport was given unbounded height.
I/flutter (18134): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter (18134): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter (18134): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter (18134): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter (18134): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter (18134): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter (18134): the height of the viewport to the sum of the heights of its children.
I/flutter (18134): 
I/flutter (18134): When the exception was thrown, this was the stack:
I/flutter (18134): #0      RenderViewport.performResize.<anonymous closure> (package:flutter/src/rendering/viewport.dart:1135:15)
I/flutter (18134): #1      RenderViewport.performResize (package:flutter/src/rendering/viewport.dart:1188:6)
I/flutter (18134): #2      RenderObject.layout (package:flutter/src/rendering/object.dart:1617:9)
I/flutter (18134): #3      _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #4      RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #5      _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #6      RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #7      _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #8      RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #9      _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #10     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #11     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #12     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #13     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #14     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #15     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #16     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #17     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #18     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #19     RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:738:15)
I/flutter (18134): #20     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #21     MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:142:11)
I/flutter (18134): #22     _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:350:7)
I/flutter (18134): #23     MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:212:7)
I/flutter (18134): #24     RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:356:14)
I/flutter (18134): #25     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #26     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #27     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #28     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #29     _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1206:11)
I/flutter (18134): #30     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #31     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #32     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #33     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #34     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #35     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #36     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #37     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #38     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #39     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #40     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #41     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #42     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #43     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #44     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #45     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #46     RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:3032:13)
I/flutter (18134): #47     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #48     RenderStack.performLayout (package:flutter/src/rendering/stack.dart:510:15)
I/flutter (18134): #49     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #50     __RenderTheatre&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #51     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #52     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #53     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #54     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #55     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #56     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #57     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #58     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #59     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #60     _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (18134): #61     RenderObject.layout (package:flutter/src/rendering/object.dart:1632:7)
I/flutter (18134): #62     RenderView.performLayout (package:flutter/src/rendering/view.dart:151:13)
I/flutter (18134): #63     RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1507:7)
I/flutter (18134): #64     PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:766:18)
I/flutter (18134): #65     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:329:19)
I/flutter (18134): #66     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:701:13)
I/flutter (18134): #67     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:268:5)
I/flutter (18134): #68     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:988:15)
I/flutter (18134): #69     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:928:9)
I/flutter (18134): #70     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.scheduleWarmUpFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:749:7)
I/flutter (18134): #72     _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
I/flutter (18134): #73     _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
I/flutter (18134): #74     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
I/flutter (18134): (elided one frame from package dart:async)
I/flutter (18134): 
I/flutter (18134): The following RenderObject was being processed when the exception was fired:
I/flutter (18134):   RenderViewport#85bc5 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (18134):   creator: Viewport ← IgnorePointer-[GlobalKey#ddac3] ← Semantics ← Listener ← _GestureSemantics ←
I/flutter (18134):   RawGestureDetector-[LabeledGlobalKey<RawGestureDetectorState>#142b9] ← _ScrollableScope ←
I/flutter (18134):   _ScrollSemantics-[GlobalKey#1902d] ← RepaintBoundary ← CustomPaint ← RepaintBoundary ←
I/flutter (18134):   NotificationListener<ScrollNotification> ← ⋯
I/flutter (18134):   parentData: <none> (can use size)
I/flutter (18134):   constraints: BoxConstraints(0.0<=w<=411.4, 0.0<=h<=Infinity)
I/flutter (18134):   size: MISSING
I/flutter (18134):   axisDirection: down
I/flutter (18134):   crossAxisDirection: right
I/flutter (18134):   offset: ScrollPositionWithSingleContext#06797(offset: 0.0, range: null..null, viewport: null,
I/flutter (18134):   ScrollableState, AlwaysScrollableScrollPhysics -> ClampingScrollPhysics, IdleScrollActivity#c3663,
I/flutter (18134):   ScrollDirection.idle)
I/flutter (18134):   anchor: 0.0
I/flutter (18134): This RenderObject had the following descendants (showing up to depth 5):
I/flutter (18134):   RenderSliverPadding#e7182 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (18134):     RenderSliverList#6b5c0 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (18134): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderViewport#85bc5 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderViewport#85bc5 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#c5ace relayoutBoundary=up9 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#f4095 relayoutBoundary=up8 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderPointerListener#1d571 relayoutBoundary=up7 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#5cee1 relayoutBoundary=up6 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: _RenderScrollSemantics#1f2eb relayoutBoundary=up5 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#70e3d relayoutBoundary=up4 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderCustomPaint#b103f relayoutBoundary=up3 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#4b75f relayoutBoundary=up2 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: RenderBox was not laid out: RenderFlex#aaf3d relayoutBoundary=up1 NEEDS-PAINT
I/flutter (18134): Another exception was thrown: NoSuchMethodError: The method '<=' was called on null.
Reloaded 2 of 573 libraries in 1,622ms.

Answer 1

你必须给父母Container一个height作为listview和Column小部件扩展以匹配他们的父母的高度，在你的情况下是Container。尝试使用MediaQuery给它屏幕高度如果你没有任何特定的大小：

    body: new Container(
    height: MediaQuery.of(context).size.height, // This will make the size of it the same as the device screen
    child: new FutureBuilder<DeckCardResponse>(
    future: fetchDecksFromFirebase(),
    builder: (context, snapshot) {

        if (snapshot.hasData) {
            return new CardPage(snapshot.data.getDecks());

        }
        else if (snapshot.hasError) {
            return new MessageError(499);

        }
        return new CircularProgressIndicator(strokeWidth: 5.0);
    }),
)