您好，下面的代码flutter用一个构造函数方法创建了一系列对象组成的listview，然后将这些对象插入视图中，代码为 new Scaffold（ 正文：新地图（不显示任何内容，并在下面显示错误，我该如何解决？我声明这是很奇怪的事情
错误：
'package:flutter/src/rendering/object.dart': Failed assertion: line 1697 pos 12: '!_debugDoingThisLayout': is not true.
Flutter代码：
class MyDiaryScreen extends StatefulWidget {
const MyDiaryScreen({Key key, this.animationController}) : super(key: key);
final AnimationController animationController;
@override
_MyDiaryScreenState createState() => _MyDiaryScreenState();
}
class _MyDiaryScreenState extends State<MyDiaryScreen>
with TickerProviderStateMixin {
List<Widget> listViews = <Widget>[];
final ScrollController scrollController = ScrollController();
Animation<double> topBarAnimation;
double topBarOpacity = 0.0;
final controller = MapController(
location: LatLng(35.68, 51.41),
);
void _incrementCounter() {
controller.location = LatLng(35.68, 51.41);
}
@override
void initState() {
topBarAnimation = Tween<double>(begin: 0.0, end: 1.0).animate(
CurvedAnimation(
parent: widget.animationController,
curve: Interval(0, 0.5, curve: Curves.fastOutSlowIn)));
addAllListData();
scrollController.addListener(() {
if (scrollController.offset >= 24) {
if (topBarOpacity != 1.0) {
setState(() {
topBarOpacity = 1.0;
});
}
} else if (scrollController.offset <= 24 &&
scrollController.offset >= 0) {
if (topBarOpacity != scrollController.offset / 24) {
setState(() {
topBarOpacity = scrollController.offset / 24;
});
}
} else if (scrollController.offset <= 0) {
if (topBarOpacity != 0.0) {
setState(() {
topBarOpacity = 0.0;
});
}
}
});
super.initState();
}
void addAllListData() {
const int count = 9;
//Prima view che comprende il titolo della Posizione
listViews.add(
TitleView(
titleTxt: 'Posizione',
subTxt: '',
animation: Tween<double>(begin: 0.0, end: 1.0).animate(CurvedAnimation(
parent: widget.animationController,
curve:
Interval((1 / count) * 0, 1.0, curve: Curves.fastOutSlowIn))),
animationController: widget.animationController,
),
);
//Inserimento del modulo con le informazioni sulla posizione
listViews.add(
MediterranesnDietView(
animation: Tween<double>(begin: 0.0, end: 1.0).animate(CurvedAnimation(
parent: widget.animationController,
curve:
Interval((1 / count) * 1, 1.0, curve: Curves.fastOutSlowIn))),
animationController: widget.animationController,
),
);
//Inserimento del titolo di registrazione
listViews.add(
TitleView(
titleTxt: 'Registrazione',
subTxt: '',
animation: Tween<double>(begin: 0.0, end: 1.0).animate(CurvedAnimation(
parent: widget.animationController,
curve:
Interval((1 / count) * 2, 1.0, curve: Curves.fastOutSlowIn))),
animationController: widget.animationController,
),
);
//Inserimento dei button per il marcatempo
listViews.add(
MarcaTempoListView(
mainScreenAnimation: Tween<double>(begin: 0.0, end: 1.0).animate(
CurvedAnimation(
parent: widget.animationController,
curve: Interval((1 / count) * 3, 1.0,
curve: Curves.fastOutSlowIn))),
mainScreenAnimationController: widget.animationController,
),
);
//Aggiunta della mappa alla lista
listViews.add(
new Scaffold(
body: new Map(
controller: controller,
provider: const CachedGoogleMapProvider(),
))
); // This trailing comma makes auto-formatting nicer for build methods.
}
Future<bool> getData() async {
await Future<dynamic>.delayed(const Duration(milliseconds: 50));
return true;
}
Widget getMainListViewUI() {
return FutureBuilder<bool>(
future: getData(),
builder: (BuildContext context, AsyncSnapshot<bool> snapshot) {
if (!snapshot.hasData) {
return const SizedBox();
} else {
return ListView.builder(
shrinkWrap: true,
controller: scrollController,
padding: EdgeInsets.only(
top: AppBar().preferredSize.height +
MediaQuery.of(context).padding.top +
24,
bottom: 62 + MediaQuery.of(context).padding.bottom,
),
itemCount: listViews.length,
scrollDirection: Axis.vertical,
itemBuilder: (BuildContext context, int index) {
widget.animationController.forward();
return listViews[index];
},
);
}
},
);
}
//Recupero della barra per la UI
Widget getAppBarUI() {
return Column(
children: <Widget>[
AnimatedBuilder(
animation: widget.animationController,
builder: (BuildContext context, Widget child) {
return FadeTransition(
opacity: topBarAnimation,
child: Transform(
transform: Matrix4.translationValues(
0.0, 30 * (1.0 - topBarAnimation.value), 0.0),
child: Container(
decoration: BoxDecoration(
color: TemaApp.white.withOpacity(topBarOpacity),
borderRadius: const BorderRadius.only(
bottomLeft: Radius.circular(32.0),
),
boxShadow: <BoxShadow>[
BoxShadow(
color: TemaApp.grey.withOpacity(0.4 * topBarOpacity),
offset: const Offset(1.1, 1.1),
blurRadius: 10.0),
],
),
child: Column(
children: <Widget>[
SizedBox(
height: MediaQuery.of(context).padding.top,
),
Padding(
padding: EdgeInsets.only(
left: 16,
right: 16,
top: 16 - 8.0 * topBarOpacity,
bottom: 12 - 8.0 * topBarOpacity),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'Marcatempo',
textAlign: TextAlign.left,
style: TextStyle(
fontFamily: TemaApp.fontName,
fontWeight: FontWeight.w700,
fontSize: 22 + 6 - 6 * topBarOpacity,
letterSpacing: 1.2,
color: TemaApp.darkerText,
),
),
),
),
],
),
)
],
),
),
),
);
},
)
],
);
}
@override
Widget build(BuildContext context) {
return Container(
color: TemaApp.background,
child: Scaffold(
backgroundColor: Colors.transparent,
body: Stack(
children: <Widget>[
//getMap(),
getMainListViewUI(),
getAppBarUI(),
SizedBox(
height: MediaQuery.of(context).padding.bottom,
)
],
),
),
);
}
}
/// You can enable caching by using [CachedNetworkImageProvider] from cached_network_image package.
class CachedGoogleMapProvider extends MapProvider {
const CachedGoogleMapProvider();
@override
ImageProvider getTile(int x, int y, int z) {
//Can also use CachedNetworkImageProvider.
return NetworkImage(
'https://www.google.com/maps/vt/pb=!1m4!1m3!1i$z!2i$x!3i$y!2m3!1e0!2sm!3i420120488!3m7!2sen!5e1105!12m4!1e68!2m2!1sset!2sRoadmap!4e0!5m1!1e0!23i4111425');
}
}