我使用 bloc 和 flutter 来处理业务逻辑等，代码工作正常，除了当我从主屏幕导航到另一个屏幕时，返回主屏幕后，来自 api 的所有数据都会丢失，它显示没有产品文本，除非我刷新 UI，任何帮助将不胜感激，谢谢
class HomePage extends StatefulWidget {
const HomePage({super.key});
@override
State<HomePage> createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
@override
void initState() {
super.initState();
BlocProvider.of<AppBloc>(context).add(UserInfoEvent());
BlocProvider.of<ProductBloc>(context).add(GetProductsEvent("electronics"));
}
@override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
body: Padding(
padding: const EdgeInsets.all(20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
BlocBuilder<AppBloc,AppState>(
builder: (context,state){
if(state is UserInfoState){
UserModel? userModel = state.userModel;
return Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(userModel!.fullName,style: Utils.getMedium().copyWith(fontSize: 20),),
const Spacer(),
CircleAvatar(
radius: 17,
backgroundColor: Colors.grey.shade200,
child: IconButton(onPressed: (){
Get.toNamed(AppRouting.cartPage);
}, icon: const Icon(Icons.add_shopping_cart_outlined,size: 15,)),
),
const SizedBox(width: 10,),
CircleAvatar(
radius: 15,
child: Image.network(userModel.profileUrl,fit: BoxFit.cover,filterQuality: FilterQuality.high,),
)
],
);
}
return Container();
},
),
const Divider(),
const SizedBox(height: 25,),
CarouselSlider(
items: Utils.banners.map((e){
return ClipRRect(
borderRadius: BorderRadius.circular(12),
child: Image.asset(e,fit: BoxFit.cover,),
);
}).toList(),
options: CarouselOptions(
viewportFraction: 1.0,
autoPlay: true,
autoPlayInterval: const Duration(seconds: 3)
)),
const SizedBox(height: 20,),
Text("Categories",style: Utils.getBold().copyWith(fontSize: 20),),
const SizedBox(height: 20,),
SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: Row(
children: List.generate(Utils.categories.length, (index) {
return GestureDetector(
onTap: () {
BlocProvider.of<ProductBloc>(context).add(GetProductsEvent(Utils.categoriesNames[index].toLowerCase()));
},
child: Card(
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12),
side: const BorderSide(color: Colors.black87)),
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
SizedBox(
width: 20,
height: 20,
child: Center(
child: Image.asset(Utils.categories[index], width: 40, height: 40),
),
),
const SizedBox(width: 10),
Text(Utils.categoriesNames[index].capitalize!),
],
),
),
),
);
}),
),
),
const SizedBox(height: 20,),
Expanded(
child: BlocBuilder<ProductBloc,AppState>(
builder: (context,state){
if(state is LOADING){
return const Center(child: SpinKitFadingCube(color: Colors.blue,size: 20,),);
}
else if (state is ERROR){
return Center(child: Text('No Products',style: Utils.getBold().copyWith(fontSize: 25),),);
}
else if(state is GetProductsState){
List<Product>? data = state.list;
return GridView.builder(
restorationId: 'store_data',
shrinkWrap: true,
itemCount: data?.length,
gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,
childAspectRatio: 0.85,
),
itemBuilder: (context,index){
return GestureDetector(
onTap: (){
Get.toNamed(AppRouting.detailsPage,arguments: { "productID" : data[index].id});
},
child: Card(
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12),
side: const BorderSide(color: Colors.black26)),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
const SizedBox(height: 20,),
Center(
child: Stack(
children: [
CachedNetworkImage(
imageUrl: data![index].image,
height: 150,
width: 150,
imageBuilder: (context, imageProvider) {
return Container(
decoration: BoxDecoration(
image: DecorationImage(image: imageProvider, fit: BoxFit.fill),
),
);
},
placeholder: (context, url) => const SizedBox(
height: 140,
width: 140,
child: Center(
child: SpinKitFadingCube(
color: Colors.blue,
size: 20,
),
),
),
errorWidget: (context, url, error) => const Icon(Icons.error),
),
Positioned(
right: 0,
top: 10,
child: Container(
width: 80,
height: 30,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(18),
color: Colors.red
),
child: Center(
child: Text("50% OFF",style: Utils.getBold().copyWith(color: Colors.white),),
),
),
)
],
),
),
Padding(
padding: const EdgeInsets.only(left: 8,right: 8,top: 4),
child: Text(data[index].title,maxLines: 1,overflow: TextOverflow.ellipsis,
style: Utils.getMedium().copyWith(fontSize: 18),),
),
Padding(
padding: const EdgeInsets.only(left: 8,right: 8),
child: Text("\$${data[index].price}",style: Utils.getBold()
.copyWith(color: Colors.blue,fontSize: 17),),
)
],
),
),
);
});
}
return Center(child: Text('No Products',style: Utils.getBold().copyWith(fontSize: 25),),);
},
))
],
),
),
),
);
}
}
问 Hitarth Chhuncha @hitarth 来自 优秀的网络世界