Flutter 方法'_mulFromInteger';被调用为空
升级了flutter后,我运行应用程序时出错。错误是“对null调用了方法'\u mulFromInteger'。问题是dart无法在持续时间内识别我的整数。在升级颤振之前,它工作正常 但我没有找到任何解决这个问题的办法。非常感谢你在这件事上的帮助Flutter 方法'_mulFromInteger';被调用为空,flutter,dart,Flutter,Dart,升级了flutter后,我运行应用程序时出错。错误是“对null调用了方法'\u mulFromInteger'。问题是dart无法在持续时间内识别我的整数。在升级颤振之前,它工作正常 但我没有找到任何解决这个问题的办法。非常感谢你在这件事上的帮助 class _SplashScreenState extends State<SplashScreen> { var noic; var nama; var majikan; var notel; int idkate
class _SplashScreenState extends State<SplashScreen> {
var noic;
var nama;
var majikan;
var notel;
int idkategori;
Future<void> checkUserStatus() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
noic = prefs.getString('sessmatrik');
nama = prefs.getString('sessnama');
notel = prefs.getString('sessnotel');
majikan = prefs.getString('sessmajikan');
idkategori= prefs.getInt('sessid');
if (noic == null) {
Navigator.pushReplacement(context, MaterialPageRoute(builder: (context) => LoginPage()));
} else {
Navigator.pushReplacement(context, MaterialPageRoute(builder: (context) =>
Dashboard(noic, nama, notel, majikan, idkategori)));
}
}
@override
void initState() {
super.initState();
Timer(
new Duration(seconds:2), checkUserStatus);
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
fit: StackFit.expand,
children: <Widget>[
Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topLeft,
end: Alignment.bottomCenter,
stops: [0.3, 0.6, 0.9],
colors: [
Color.fromRGBO(12, 235, 235, 1),
Color.fromRGBO(32, 227, 178, 1),
Color.fromRGBO(41, 255, 198, 1),
],
),
),
),
Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Expanded(
flex: 2,
child: Container(
padding: EdgeInsets.all(20.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 10.0),
),
Image.asset('assets/images/myk3k.png', scale: 0.1,),
],
),
),
),
Expanded(
flex: 1,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
CircularProgressIndicator(),
Padding(
padding: EdgeInsets.only(top: 20.0),
),
Text(
'Loading',
softWrap: true,
textAlign: TextAlign.center,
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 18.0,
color: Colors.white),
)
],
),
)
],
)
],
),
);
}
}
class\u屏幕状态扩展状态{
无变种;
var nama;
var majikan;
var notel;
伊德卡泰戈里国际酒店;
Future checkUserStatus()异步{
SharedReferences prefs=等待SharedReferences.getInstance();
noic=prefs.getString('sessmatrik');
nama=prefs.getString('sessnama');
notel=prefs.getString('sessnotel');
majikan=prefs.getString('sessmajikan');
idkategori=prefs.getInt('sessiond');
if(noic==null){
pushReplacement(上下文,materialpage(builder:(context)=>LoginPage());
}否则{
Navigator.pushReplacement(上下文,MaterialPage路由(生成器:(上下文)=>
仪表板(noic、nama、notel、majikan、idkategori);
}
}
@凌驾
void initState(){
super.initState();
计时器(
新的持续时间(秒数:2),检查用户状态;
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
主体:堆栈(
fit:StackFit.expand,
儿童:[
容器(
装饰:盒子装饰(
梯度:线性梯度(
开始:Alignment.topLeft,
结束:对齐。底部中心,
停止:[0.3,0.6,0.9],
颜色:[
颜色。来自RGBO(12,235,235,1),
颜色。来自RGBO(32227178,1),
颜色。来自RGBO(41255198,1),
],
),
),
),
纵队(
mainAxisAlignment:mainAxisAlignment.start,
儿童:[
扩大(
弹性:2,
子:容器(
填充:所有边缘设置(20.0),
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
填充物(
填充:仅限边缘设置(顶部:10.0),
),
Image.asset('assets/images/myk3k.png',比例:0.1,),
],
),
),
),
扩大(
弹性:1,
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
CircularProgressIndicator(),
填充物(
填充:仅限边缘设置(顶部:20.0),
),
正文(
“加载”,
软包装:是的,
textAlign:textAlign.center,
样式:TextStyle(
fontWeight:fontWeight.bold,
字体大小:18.0,
颜色:颜色。白色),
)
],
),
)
],
)
],
),
);
}
}
这是否回答了您的问题?