Flutter-My 提供程序在调用更新方法后似乎没有通知其侦听器

Question

我有一个CupertinoTabView与3选项卡。我的问题与第一个有关，它显示了一些送货信息。我们可以通过单击列表中每个项目的更新按钮来更新交付状态，这将使用Navigator.push()将我们带到另一个名为UpdateDeliveryStatusScreen的屏幕。发送更新请求并返回响应之后，我们使用Navigator.pop()返回交付列表。我使用提供程序进行状态管理。但是，当我返回交付列表时，状态仍然没有更新，即使一切正常，提供者中的交付列表也更新了。以下是我的代码:

MainScreen:

...
CupertinoTabScaffold(
resizeToAvoidBottomInset: true,
tabBar: CupertinoTabBar(
onTap: onTabTapped,
items: const [
BottomNavigationBarItem(
icon: Icon(Icons.home),
label: 'Home',
),
BottomNavigationBarItem(
icon: Icon(Icons.calendar_month),
label: 'Availability',
),
BottomNavigationBarItem(
icon: Icon(Icons.person),
label: 'Profile',
),
],
),
tabBuilder: (context, index) {
var currentWidget;
if (index == 0) {
currentWidget = CupertinoTabView(
navigatorKey: firstTabNavKey,
builder: (BuildContext context) => Consumer<DeliveryProvider>(
builder: (_, value, child) => DeliveryWidget(),
),
);
} 
...

DeliveryWidget:

class DeliveryWidget extends StatefulWidget {
/* final List<Delivery> deliveries;
HomeWidget({required this.deliveries}); */
@override
State<DeliveryWidget> createState() => _DeliveryWidgetState();
}
class _DeliveryWidgetState extends State<DeliveryWidget> {
List<Item> _data = [];
Future<void> initData() async {
final deliveryProvider =
Provider.of<DeliveryProvider>(context, listen: false);
await deliveryProvider.getDeliveries(context);
final deliveries = deliveryProvider.deliveries;
deliveries.forEach((element) {
_data.add(generateItem(element));
});
}
@override
void initState() {
super.initState();
initData();
}
Color? getStatusColor(String status) {
Color? color;
if (status == 'Received') {
color = Colors.green;
} else if (status == 'Dispatched') {
color = Colors.yellow;
} else if (status == 'In Transit') {
color = Colors.orange;
} else if (status == 'Delivered') {
color = Colors.red;
}
return color;
}
String getButtonText(String status) {
String text = '';
if (status == 'In Transit') {
text = 'pin code';
} else {
text = 'update';
}
return text;
}
@override
Widget build(BuildContext context) {
return SingleChildScrollView(
child: _data.isNotEmpty
? _buildPanel()
: const Center(
child: Text('No data found'),
),
);
}
Widget _buildPanel() {
var width = MediaQuery.of(context).size.width;
return ExpansionPanelList(
expansionCallback: (int index, bool isExpanded) {
setState(() {
_data[index].isExpanded = !isExpanded;
});
},
children: _data.map<ExpansionPanel>((Item item) {
return ExpansionPanel(
headerBuilder: (BuildContext context, bool isExpanded) {
return ListTile(
leading: FittedBox(
fit: BoxFit.fitWidth,
child: Text(
item.delivery.orderNr,
style: const TextStyle(
fontSize: 10,
fontWeight: FontWeight.bold,
color: Colors.red),
),
),
title: FittedBox(
fit: BoxFit.fitWidth,
child: Text(
'from: ${item.delivery.origin}nto: ${item.delivery.destination}'),
),
trailing: SizedBox(
width: 100,
child: Row(children: [
Container(
width: 12,
height: 12,
decoration: BoxDecoration(
shape: BoxShape.circle,
color: getStatusColor(item.delivery.status)),
),
const SizedBox(
width: 10,
),
Text(item.delivery.status)
]),
),
);
},
body: ListTile(
leading: SizedBox(
width: width * 0.3,
child: Text(
'Weight: ${item.delivery.weight} kg',
),
),
title:
SizedBox(width: width * 0.4, child: Text(item.delivery.type)),
subtitle: SizedBox(
width: width * 0.4,
child: Text('HxWxD: ${item.delivery.dimensions}')),
trailing: SizedBox(
width: width * 0.2,
child: FittedBox(
fit: BoxFit.fitWidth,
child: Column(
children: [
Row(
children: [
IconButton(
onPressed: () => null, icon: Icon(Icons.comment)),
IconButton(
onPressed: () => null, icon: Icon(Icons.person))
],
),
CupertinoButton(
padding: EdgeInsets.zero,
onPressed: () => Navigator.push(
context,
MaterialPageRoute(
builder: (context) => UpdateDeliveryStatusScreen(),
settings: RouteSettings(
arguments: {'delivery': item.delivery.toJson()},
),
),
),
child: Text(
getButtonText(item.delivery.status),
),
)
],
),
)),
),
isExpanded: item.isExpanded,
);
}).toList(),
);
}
}
class Item extends ChangeNotifier {
Delivery delivery;
bool isExpanded;
Item({required this.delivery, this.isExpanded = false});
}
Item generateItem(Delivery delivery) {
return Item(delivery: delivery);
}

UpdateDeliveryScreen(只是更新部分):

await DeliveryService.updateDeliveryStatus(body, delivery.id)
.then((Delivery newDelivery) {
final prov =
Provider.of<DeliveryProvider>(context, listen: false);
prov.updateDelivery(newDelivery);
prov.deliveries.forEach((element) {
print(element.status);
});
Navigator.of(context).pop();
});

DeliveryProvider:

class DeliveryProvider with ChangeNotifier {
List<Delivery> deliveries = [];
Future<void> getDeliveries(context) async {
deliveries = await DeliveryService.getDeliveries();
notifyListeners();
}
void updateDelivery(Delivery delivery) {
deliveries[deliveries.indexWhere((a) => a.id == delivery.id)] = delivery;
notifyListeners();
}
}

很抱歉写了这么多代码。我尽量把它写得简短些。如果你还需要什么，请告诉我。提前谢谢。

注。状态在后端更新成功，而不是UI。

Answer 1

你试过了吗:

Navigator.push(...).then((value)=> setState((){}));

这样UI就会被另一个屏幕的弹出更新。