又抛出一个异常:setState() or markNeedsBuild() called during build Error in flutter
Another exception was thrown: setState() or markNeedsBuild() called during build Error in flutter
我是 Flutter 的新手,正在开发电子商务 Flutter 应用程序。当我试图导航到搜索屏幕时,它给出了一些错误。请找到以下代码供您参考并帮助解决。
错误:
在为 SearchProvider 发送通知时抛出以下断言:
setState() 或 markNeedsBuild() 在构建期间调用。
此 _InheritedProviderScope 小部件无法标记为需要构建,因为
该框架已经在构建小部件的过程中。一个小部件可以被标记为需要
仅当其祖先之一当前正在构建时,才在构建阶段构建。这个异常
是允许的,因为框架在子部件之前构建父部件,这意味着脏
后代将永远被建造。否则,框架可能不会在此期间访问此小部件
构建阶段。
调用 setState() 或 markNeedsBuild() 的小部件是:
_InheritedProviderScope
进行违规调用时当前正在构建的小部件是:
搜索屏幕
代码
搜索屏幕
class SearchScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
Provider.of<SearchProvider>(context, listen: false).cleanSearchProduct();
Provider.of<SearchProvider>(context, listen: false).initHistoryList();
return Scaffold(
backgroundColor: ColorResources.getIconBg(context),
resizeToAvoidBottomInset: true,
body: Column(
children: [
// for tool bar
SearchWidget(
hintText: getTranslated('SEARCH_HINT', context),
onSubmit: (String text) {
Provider.of<SearchProvider>(context, listen: false)
.searchProduct(text, context);
Provider.of<SearchProvider>(context, listen: false)
.saveSearchAddress(text);
},
onClearPressed: () {
Provider.of<SearchProvider>(context, listen: false)
.cleanSearchProduct();
},
),
Consumer<SearchProvider>(
builder: (context, searchProvider, child) {
return !searchProvider.isClear
? searchProvider.searchProductList != null
? searchProvider.searchProductList.length > 0
? Expanded(
child: SearchProductWidget(
products: searchProvider.searchProductList,
isViewScrollable: true))
: Expanded(
child:
NoInternetOrDataScreen(isNoInternet: false))
: Expanded(
child: ProductShimmer(
isHomePage: false,
isEnabled: Provider.of<SearchProvider>(context)
.searchProductList ==
null))
: Expanded(
flex: 4,
child: Container(
padding:
EdgeInsets.all(Dimensions.PADDING_SIZE_DEFAULT),
child: Stack(
clipBehavior: Clip.none,
children: [
Consumer<SearchProvider>(
builder: (context, searchProvider, child) =>
StaggeredGridView.countBuilder(
crossAxisCount: 3,
physics: NeverScrollableScrollPhysics(),
itemCount: searchProvider.historyList.length,
itemBuilder: (context, index) => Container(
alignment: Alignment.center,
child: InkWell(
onTap: () {
Provider.of<SearchProvider>(context,
listen: false)
.searchProduct(
searchProvider
.historyList[index],
context);
},
borderRadius: BorderRadius.circular(20),
child: Container(
padding: EdgeInsets.only(
left: 10,
right: 10,
top: 2,
bottom: 2),
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(16),
color: ColorResources.getGrey(
context)),
width: double.infinity,
child: Center(
child: Text(
Provider.of<SearchProvider>(context,
listen: false)
.historyList[index] ??
"",
style: titilliumItalic.copyWith(
fontSize:
Dimensions.FONT_SIZE_SMALL),
),
),
),
)),
staggeredTileBuilder: (int index) =>
new StaggeredTile.fit(1),
mainAxisSpacing: 4.0,
crossAxisSpacing: 4.0,
),
),
Positioned(
top: -5,
left: 0,
right: 0,
child: Row(
mainAxisAlignment:
MainAxisAlignment.spaceBetween,
children: [
Text(getTranslated('SEARCH_HISTORY', context),
style: robotoBold),
InkWell(
borderRadius: BorderRadius.circular(10),
onTap: () {
Provider.of<SearchProvider>(context,
listen: false)
.clearSearchAddress();
},
child: Container(
padding: EdgeInsets.all(5),
child: Text(
getTranslated('REMOVE', context),
style: titilliumRegular.copyWith(
fontSize:
Dimensions.FONT_SIZE_SMALL,
color: Theme.of(context)
.primaryColor),
)))
],
),
),
],
),
),
);
},
),
],
),
);
}
}
提供商
void initHistoryList() {
_historyList = [];
_historyList.addAll(searchRepo.getSearchAddress());
notifyListeners();
}
void cleanSearchProduct() {
_searchProductList = [];
_isClear = true;
_searchText = '';
notifyListeners();
}
尝试在 initState
中使用初始函数调用而不是构建函数
@override
void initState() {
WidgetsBinding.instance!.addPostFrameCallback((_) {
Provider.of<SearchProvider>(context, listen: false).cleanSearchProduct();
Provider.of<SearchProvider>(context, listen: false).initHistoryList();
});
super.initState();
}
我是 Flutter 的新手,正在开发电子商务 Flutter 应用程序。当我试图导航到搜索屏幕时,它给出了一些错误。请找到以下代码供您参考并帮助解决。
错误:
在为 SearchProvider 发送通知时抛出以下断言:
setState() 或 markNeedsBuild() 在构建期间调用。
此 _InheritedProviderScope
代码 搜索屏幕
class SearchScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
Provider.of<SearchProvider>(context, listen: false).cleanSearchProduct();
Provider.of<SearchProvider>(context, listen: false).initHistoryList();
return Scaffold(
backgroundColor: ColorResources.getIconBg(context),
resizeToAvoidBottomInset: true,
body: Column(
children: [
// for tool bar
SearchWidget(
hintText: getTranslated('SEARCH_HINT', context),
onSubmit: (String text) {
Provider.of<SearchProvider>(context, listen: false)
.searchProduct(text, context);
Provider.of<SearchProvider>(context, listen: false)
.saveSearchAddress(text);
},
onClearPressed: () {
Provider.of<SearchProvider>(context, listen: false)
.cleanSearchProduct();
},
),
Consumer<SearchProvider>(
builder: (context, searchProvider, child) {
return !searchProvider.isClear
? searchProvider.searchProductList != null
? searchProvider.searchProductList.length > 0
? Expanded(
child: SearchProductWidget(
products: searchProvider.searchProductList,
isViewScrollable: true))
: Expanded(
child:
NoInternetOrDataScreen(isNoInternet: false))
: Expanded(
child: ProductShimmer(
isHomePage: false,
isEnabled: Provider.of<SearchProvider>(context)
.searchProductList ==
null))
: Expanded(
flex: 4,
child: Container(
padding:
EdgeInsets.all(Dimensions.PADDING_SIZE_DEFAULT),
child: Stack(
clipBehavior: Clip.none,
children: [
Consumer<SearchProvider>(
builder: (context, searchProvider, child) =>
StaggeredGridView.countBuilder(
crossAxisCount: 3,
physics: NeverScrollableScrollPhysics(),
itemCount: searchProvider.historyList.length,
itemBuilder: (context, index) => Container(
alignment: Alignment.center,
child: InkWell(
onTap: () {
Provider.of<SearchProvider>(context,
listen: false)
.searchProduct(
searchProvider
.historyList[index],
context);
},
borderRadius: BorderRadius.circular(20),
child: Container(
padding: EdgeInsets.only(
left: 10,
right: 10,
top: 2,
bottom: 2),
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(16),
color: ColorResources.getGrey(
context)),
width: double.infinity,
child: Center(
child: Text(
Provider.of<SearchProvider>(context,
listen: false)
.historyList[index] ??
"",
style: titilliumItalic.copyWith(
fontSize:
Dimensions.FONT_SIZE_SMALL),
),
),
),
)),
staggeredTileBuilder: (int index) =>
new StaggeredTile.fit(1),
mainAxisSpacing: 4.0,
crossAxisSpacing: 4.0,
),
),
Positioned(
top: -5,
left: 0,
right: 0,
child: Row(
mainAxisAlignment:
MainAxisAlignment.spaceBetween,
children: [
Text(getTranslated('SEARCH_HISTORY', context),
style: robotoBold),
InkWell(
borderRadius: BorderRadius.circular(10),
onTap: () {
Provider.of<SearchProvider>(context,
listen: false)
.clearSearchAddress();
},
child: Container(
padding: EdgeInsets.all(5),
child: Text(
getTranslated('REMOVE', context),
style: titilliumRegular.copyWith(
fontSize:
Dimensions.FONT_SIZE_SMALL,
color: Theme.of(context)
.primaryColor),
)))
],
),
),
],
),
),
);
},
),
],
),
);
}
}
提供商
void initHistoryList() {
_historyList = [];
_historyList.addAll(searchRepo.getSearchAddress());
notifyListeners();
}
void cleanSearchProduct() {
_searchProductList = [];
_isClear = true;
_searchText = '';
notifyListeners();
}
尝试在 initState
中使用初始函数调用而不是构建函数
@override
void initState() {
WidgetsBinding.instance!.addPostFrameCallback((_) {
Provider.of<SearchProvider>(context, listen: false).cleanSearchProduct();
Provider.of<SearchProvider>(context, listen: false).initHistoryList();
});
super.initState();
}