我正在尝试使用列布局在卡片小部件内显示ListView，但是卡片小部件未出现在屏幕上，并且出现错误消息。但是，当我更改为堆栈布局时，该小部件会出现在屏幕上，但不是我想要的其他组件的顶部。
在下面的代码中查看我的卡小部件
import 'package:flutter/material.dart';
import 'package:finsec/widget/cardview_list_widget.dart';
import 'package:finsec/widget/header.dart';
import 'package:finsec/widget/vertical_padding.dart';
import 'package:finsec/data/cardview_list_item.dart';
final shape = const RoundedRectangleBorder(
borderRadius: BorderRadius.only(
topLeft: Radius.circular(8.0),
topRight: Radius.circular(8.0),
bottomLeft: Radius.circular(8.0),
bottomRight: Radius.circular(8.0),
)
);
Widget cardView(BuildContext context) {
return Padding(
padding: EdgeInsets.fromLTRB(0.0,15.0,0.0,0.0) ,
child: new Card(
elevation: 4.0,
shape: shape,
child: new Container(
width: MediaQuery.of(context).size.width ,
height: 200,
child: new Column(
children: <Widget>[
Header(text: 'Summary', textSize: 24.0, backgroundColor: Color(0xffC4C4C4), textColor: Colors.black, height: 50, padding: 20.0, headerRadius: 8.0,),
myListView(),
],
),
),
),
);
}
下面是我的ListView小部件的代码：
import 'package:flutter/material.dart';
import 'package:finsec/data/cardview_list_item.dart';
class myListView extends StatelessWidget {
@override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: kCardviewListItems.length,
itemBuilder: (context, index) {
return ListTile(
leading: Icon(kCardviewListItems[index].icon),
title: Align(
child: new Text(kCardviewListItems[index].title),
alignment: Alignment(-1.4, 0),
),
trailing: Text(kCardviewListItems[index].amount),
);
},
);
}
}
以下是ListView的数据：
import 'package:finsec/model/cardview_list_item.dart';
import 'package:flutter/material.dart';
const kCardviewListItems = <CardviewListItem>[
CardviewListItem(
title: 'Total Income',
amount:'4434.65',
icon: Icons.credit_card
),
CardviewListItem(
title: 'Total Expenses',
amount:'753.64',
icon: Icons.credit_card
),
CardviewListItem(
title: 'Total Credit Card',
amount:'75.23',
icon: Icons.credit_card
),
];
IDE上的错误如下：
I/flutter (25995): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (25995): The following assertion was thrown during performResize():
I/flutter (25995): Vertical viewport was given unbounded height.
I/flutter (25995): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter (25995): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter (25995): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter (25995): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter (25995): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter (25995): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter (25995): the height of the viewport to the sum of the heights of its children.
I/flutter (25995):
I/flutter (25995): When the exception was thrown, this was the stack:
I/flutter (25995): #0 RenderViewport.performResize.<anonymous closure> (package:flutter/src/rendering/viewport.dart:1135:15)
I/flutter (25995): #1 RenderViewport.performResize (package:flutter/src/rendering/viewport.dart:1188:6)
I/flutter (25995): #2 RenderObject.layout (package:flutter/src/rendering/object.dart:1629:9)
I/flutter (25995): #3 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (25995): #4 RenderObject.layout (package:flutter/src/rendering/object.dart:1644:7)
I/flutter (25995): #5 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:105:13)
I/flutter (25995): #6 RenderObject.layout (package:flutter/src/rendering/object.dart:1644:7)
I/flutter (25995): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderViewport#d1ae0 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderViewport#d1ae0 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderIgnorePointer#37bbc relayoutBoundary=up9 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#0aeed relayoutBoundary=up8 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderPointerListener#eec60 relayoutBoundary=up7 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderSemanticsGestureHandler#c725d relayoutBoundary=up6 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderPointerListener#49c66 relayoutBoundary=up5 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: _RenderScrollSemantics#ccd3a relayoutBoundary=up4 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#b19b2 relayoutBoundary=up3 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderCustomPaint#0de2e relayoutBoundary=up2 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderRepaintBoundary#8ee47 relayoutBoundary=up1 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderFlex#01dd8 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderConstrainedBox#16e60 relayoutBoundary=up12 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#dbcdc relayoutBoundary=up11 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: _RenderInkFeatures#2862e relayoutBoundary=up10 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderCustomPaint#8c3e4 relayoutBoundary=up9 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderPhysicalShape#e7aa2 relayoutBoundary=up8 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderPadding#4dcf9 relayoutBoundary=up7 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderSemanticsAnnotations#38f0f relayoutBoundary=up6 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: RenderBox was not laid out: RenderPadding#1a5eb relayoutBoundary=up5 NEEDS-PAINT
I/flutter (25995): Another exception was thrown: 'package:flutter/src/rendering/shifted_box.dart': Failed assertion: line 314 pos 12: 'child.hasSize': is not true.
I/flutter (25995): Another exception was thrown: NoSuchMethodError: The method '<=' was called on null.
我希望ListView出现在标题小部件下方。