Flutter 当在第三个屏幕中使用Flatter中的provider包进行任何更改时，如何更改第一个屏幕中的文本？
我有一个名为Include stateful widget的第一个屏幕，Flutter 当在第三个屏幕中使用Flatter中的provider包进行任何更改时，如何更改第一个屏幕中的文本？,flutter,state,state-management,Flutter,State,State Management,我有一个名为Include stateful widget的第一个屏幕，PlantFeatureScreen1，其中我必须在第三个屏幕中显示更新发生时的更改，该屏幕还包括一个stateful widget，CartDetais3 当在第三个屏幕中发生更改并且将在第三个屏幕中添加addQuantity和subtractQuantity功能时，如何更新第一个屏幕？请建议使用提供商软件包 firstScreen code这里我必须显示这个小部件树的最后一个中心小部件中的更改 class PlantFe
PlantFeatureScreen1CartDetais3addQuantitysubtractQuantityclass PlantFeatureScreen1 extends StatefulWidget {
@override
_PlantFeatureScreen1State createState() => _PlantFeatureScreen1State();
}
class _PlantFeatureScreen1State extends State<PlantFeatureScreen1> {
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
TopAppBar(),
Expanded(
flex: 1,
child: Align(
alignment: Alignment(-1, 0),
child: Container(
decoration: BoxDecoration(
color: Colors.white,
),
child: Text(
"Plants",
style: TextStyle(fontSize: 30, fontWeight: FontWeight.w700),
),
),
),
),
Expanded(
flex: 5,
child: Container(
width: double.infinity,
decoration: BoxDecoration(
color: Colors.blue,
),
child: DefaultTabController(
length: 5,
child: Column(
children: [
Container(
height: 50,
width: double.infinity,
child: TabBar(
isScrollable: true,
tabs: ourAllLists.tabMaker(),
),
),
Container(
height: 317,
width: double.infinity,
decoration: BoxDecoration(color: Colors.white),
child: TabBarView(
children: ourAllLists.tabViewerMaker(context),),),
],
),
),
),
),
Padding(
padding: const EdgeInsets.fromLTRB(20, 0, 20, 20),
child: Container(
alignment: Alignment.bottomRight,
height: 120,
width: double.infinity,
child: Stack(
overflow: Overflow.visible,
children: [
Container(
height: 70,
width: 105,
decoration: BoxDecoration(
color: Color(0xFF96CA2D),
borderRadius: BorderRadiusDirectional.horizontal(
end: Radius.circular(32),
start: Radius.circular(32))),
child: Icon(FontAwesomeIcons.shoppingBag,color:Colors.white,size:30),
),
Positioned(
// top: 0,
bottom: 50,
right: 0,
child: Container(
height: 35,
width: 35,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(50),
border: Border.all(color: Color(0xFF96CA2D),width: 4)
),
child: Center(child: Text(ourAllLists.totalquantity().toString(),style:TextStyle(fontSize: 20,color: Color(0xFF96CA2D)))),
),
)
],
),
),
)
],
);
}
}
class CartDetais3 extends StatefulWidget {
@override
_CartDetais3State createState() => _CartDetais3State();
}
class _CartDetais3State extends State<CartDetais3> {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: SafeArea(
child: Scaffold(
body: Padding(
padding: const EdgeInsets.fromLTRB(8, 20, 8, 15),
child: Column(
children: [
TopAppBar(),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(
"Cart",
style: kPlantNameStyle,
),
Text(
"\$" + "284",
style: kItemPrice,
),
],
),
Expanded(
child: ListView.builder(
itemCount: OurAllLists.cartPlantList3.length,
itemBuilder: (context, index) {
return Card(
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Container(
height: 110,
width: 100,
child: Image(image: AssetImage("assets/tulip.png")),
),
Container(
height: 80,
width: 120,
child: Column(
children: [
Text(OurAllLists.cartPlantList3[index].pN),
Text(OurAllLists.cartPlantList3[index].ca
.toUpperCase()),
Text("\$ " +
OurAllLists.cartPlantList3[index].pr
.toString()),
],
),
),
Container(
height: 120,
child: Column(
children: [
FlatButton(
onPressed: () {
setState(() {
*here addQuantity function must go*
});
},
child: Icon(
FontAwesomeIcons.plus,
size: 20,
),
),
Text(OurAllLists.cartPlantList3[index].qu
.toString()),
FlatButton(
onPressed: () {
*here subtractQuantity function must go*
},
child: Icon(
FontAwesomeIcons.minus,
size: 20,
),
),
],
))
],
),
);
}),
)
],
),
),
)));
}
}
class ViewTotalItemProvider extends ChangeNotifier{
addQuantity(index){
OurAllLists.cartPlantList3[index].qu++;
notifyListeners();
}
subtrachQuantity(index){
OurAllLists.cartPlantList3[index].qu--;
}
}