Android 步进机内的数据采集器
所以我对颤振还很陌生，这是我的第一个项目。一切都很顺利，直到这个问题出现。 最近，我在我的页面中添加了一个StepperBook，其中一个步骤应该集成了一个datePicker。不幸的是，我无法真正解决即将出现的问题。 我经常得到一个“只有静态成员才能在初始化器中访问”错误。 谢谢你的帮助 我正在使用flatter\u datetime\u picker插件 这是我的密码：Android 步进机内的数据采集器,android,ios,flutter,dart,static,Android,Ios,Flutter,Dart,Static,所以我对颤振还很陌生，这是我的第一个项目。一切都很顺利，直到这个问题出现。 最近，我在我的页面中添加了一个StepperBook，其中一个步骤应该集成了一个datePicker。不幸的是，我无法真正解决即将出现的问题。 我经常得到一个“只有静态成员才能在初始化器中访问”错误。 谢谢你的帮助 我正在使用flatter\u datetime\u picker插件 这是我的密码： class StepperBody extends StatefulWidget { @override _Ste
class StepperBody extends StatefulWidget {
@override
_StepperBodyState createState() => _StepperBodyState();
}
class _StepperBodyState extends State<StepperBody> {
String _date = "Not set";
int currStep = 0;
static var _focusNode = FocusNode();
GlobalKey<FormState> _formKey = GlobalKey<FormState>();
static MyData data = MyData();
@override
void initState() {
super.initState();
_focusNode.addListener(() {
setState(() {});
print('Has focus: $_focusNode.hasFocus');
});
}
List<Step> steps = [
Step(
title: const Text('Name',
style: TextStyle(
fontFamily: 'Maax',
fontSize: 20,
),),
//subtitle: const Text('Enter your name'),
isActive: true,
//state: StepState.error,
state: StepState.indexed,
content: Form(
key: formKeys[0],
child: Column(
children: <Widget>[
TextFormField(
style: TextStyle(
fontFamily: 'Maax',
fontWeight: FontWeight.w500,
),
focusNode: _focusNode,
keyboardType: TextInputType.text,
autocorrect: false,
onSaved: (String value) {
data.title = value;
},
maxLines: 1,
//initialValue: 'Aseem Wangoo',
validator: (value) {
if (value.isEmpty || value.length < 1) {
return 'Please enter title';
}
},
decoration: InputDecoration(
labelText: 'What is the name of the test?',
hintText: 'Enter a name',
//filled: true,
icon: const FaIcon(FontAwesomeIcons.signature),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid, fontFamily: 'Maax', fontWeight: FontWeight.w500)),
),
],
),
)),
Step(
title: const Text('Date'),
//subtitle: const Text('Subtitle'),
isActive: true,
//state: StepState.editing,
state: StepState.indexed,
content: Form(
key: formKeys[1],
child: Column(
children: <Widget>[
RaisedButton(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(5.0)),
elevation: 4.0,
onPressed: () {
DatePicker.showDatePicker(context,
theme: DatePickerTheme(
containerHeight: 210.0,
),
showTitleActions: true,
minTime: DateTime(2000, 1, 1),
maxTime: DateTime(2022, 12, 31), onConfirm: (date) {
print('confirm $date');
_date = '${date.year} - ${date.month} - ${date.day}';
setState(() {});
}, currentTime: DateTime.now(), locale: LocaleType.en);
},
child: Container(
alignment: Alignment.center,
height: 50.0,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
children: <Widget>[
Container(
child: Row(
children: <Widget>[
Icon(
Icons.date_range,
size: 18.0,
color: Colors.teal,
),
Text(
" $_date",
style: TextStyle(
color: Colors.teal,
fontWeight: FontWeight.bold,
fontSize: 18.0),
),
],
),
)
],
),
Text(
" Change",
style: TextStyle(
color: Colors.teal,
fontWeight: FontWeight.bold,
fontSize: 18.0),
),
],
),
),
color: Colors.white,
),
TextFormField(
keyboardType: TextInputType.phone,
autocorrect: false,
validator: (value) {
if (value.isEmpty || value.length < 10) {
return 'Please enter valid number';
}
},
onSaved: (String value) {
data.days = value;
},
maxLines: 1,
decoration: InputDecoration(
labelText: 'Enter your number',
hintText: 'Enter a number',
icon: const Icon(Icons.phone),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Email'),
// subtitle: const Text('Subtitle'),
isActive: true,
state: StepState.indexed,
// state: StepState.disabled,
content: Form(
key: formKeys[2],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.emailAddress,
autocorrect: false,
validator: (value) {
if (value.isEmpty || !value.contains('@')) {
return 'Please enter valid email';
}
},
onSaved: (String value) {
data.words = value;
},
maxLines: 1,
decoration: InputDecoration(
labelText: 'Enter your email',
hintText: 'Enter a email address',
icon: const Icon(Icons.email),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Age'),
// subtitle: const Text('Subtitle'),
isActive: true,
state: StepState.indexed,
content: Form(
key: formKeys[3],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.number,
autocorrect: false,
validator: (value) {
if (value.isEmpty || value.length > 2) {
return 'Please enter valid age';
}
},
maxLines: 1,
onSaved: (String value) {
data.rep = value;
},
decoration: InputDecoration(
labelText: 'Enter your age',
hintText: 'Enter age',
icon: const Icon(Icons.explicit),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
// Step(
// title: const Text('Fifth Step'),
// subtitle: const Text('Subtitle'),
// isActive: true,
// state: StepState.complete,
// content: const Text('Enjoy Step Fifth'))
];
@override
Widget build(BuildContext context) {
void showSnackBarMessage(String message,
[MaterialColor color = Colors.red]) {
Scaffold
.of(context)
.showSnackBar( SnackBar(content: Text(message)));
}
void _submitDetails() {
final FormState formState = _formKey.currentState;
if (!formState.validate()) {
showSnackBarMessage('Please enter correct data');
} else {
formState.save();
print("Name: ${data.title}");
print("Phone: ${data.days}");
print("Email: ${data.words}");
print("Age: ${data.rep}");
showDialog(
context: context,
child: AlertDialog(
title: Text("Details"),
//content: Text("Hello World"),
content: SingleChildScrollView(
child: ListBody(
children: <Widget>[
Text("Name : " + data.title),
Text("Phone : " + data.days),
Text("Email : " + data.words),
Text("Age : " + data.rep),
],
),
),
actions: <Widget>[
FlatButton(
child: Text('OK'),
onPressed: () {
Navigator.of(context).pop();
},
),
],
));
}
}
return Container(
child: Form(
key: _formKey,
child: ListView(children: <Widget>[
Stepper(
steps: steps,
type: StepperType.vertical,
currentStep: this.currStep,
onStepContinue: () {
setState(() {
if(formKeys[currStep].currentState.validate()) {
if (currStep < steps.length - 1) {
currStep = currStep + 1;
} else {
currStep = 0;
}
}
// else {
// Scaffold
// .of(context)
// .showSnackBar( SnackBar(content: Text('$currStep')));
// if (currStep == 1) {
// print('First Step');
// print('object' + FocusScope.of(context).toStringDeep());
// }
// }
});
},
onStepCancel: () {
setState(() {
if (currStep > 0) {
currStep = currStep - 1;
} else {
currStep = 0;
}
});
},
onStepTapped: (step) {
setState(() {
currStep = step;
});
},
),
RaisedButton(
child: Text(
'Save details',
style: TextStyle(color: Colors.white),
),
onPressed: _submitDetails,
color: Colors.blue,
),
]),
));
}
}
类StepperBody扩展StatefulWidget{
@凌驾
_StepherBodyState createState（）=>U StepherBodyState（）；
}
类_StepperBodyState扩展状态{
字符串_date=“未设置”；
int currStep=0；
静态变量_focusNode=focusNode（）；
GlobalKey _formKey=GlobalKey（）；
静态MyData数据=MyData（）；
@凌驾
void initState（）{
super.initState（）；
_focusNode.addListener（）{
setState（（）{}）；
打印（'Has focus:$\u focusNode.hasFocus'）；
});
}
列出步骤=[
台阶(
标题：常量文本（'名称'，
样式：TextStyle(
fontFamily：“Maax”，
尺寸：20，
),),
//字幕：常量文本（“输入您的姓名”），
是的，
//state:StepState.error，
状态：StepState.index，
内容：表格(
关键字：formKeys[0]，
子：列(
儿童：[
TextFormField(
样式：TextStyle(
fontFamily：“Maax”，
fontWeight:fontWeight.w500，
),
focusNode:_focusNode，
键盘类型：TextInputType.text，
自动更正：错误，
onSaved：（字符串值）{
data.title=值；
},
maxLines:1，
//初始值：“Aseem Wangoo”，
验证器：（值）{
if（value.isEmpty | value.length<1）{
返回“请输入标题”；
}
},
装饰：输入装饰(
labelText:“测试的名称是什么？”，
hintText:'输入名称'，
//是的，
图标：const FaIcon（FontAwesomeIcons.signature），
标签样式：
TextStyle（decorationStyle:TextDecorationStyle.solid，fontFamily:'Maax'，fontWeight:fontWeight.w500）），
),
],
),
)),
台阶(
标题：常量文本（“日期”），
//副标题：常量文本（“副标题”），
是的，
//状态：StepState.editing，
状态：StepState.index，
内容：表格(
key:formkey[1]，
子：列(
儿童：[
升起的按钮(
形状：圆形矩形边框(
边界半径：边界半径。圆形（5.0）），
标高：4.0，
已按下：（）{
DatePicker.showDatePicker（上下文，
主题：日期选取主题(
集装箱重量：210.0，
),
showttitleactions：对，
minTime:DateTime（2000,1,1），
maxTime:DateTime（2022,12,31），onConfirm:（日期）{
打印（“确认$date”）；
_日期=“${date.year}-${date.month}-${date.day}”；
setState（（）{}）；
}，currentTime:DateTime.now（），locale:LocaleType.en）；
},
子：容器(
对齐：对齐.center，
身高：50.0，
孩子：排(
mainAxisAlignment:mainAxisAlignment.spaceBetween，
儿童：[
划船(
儿童：[
容器(
孩子：排(
儿童：[
图标(
Icons.date\u范围，
尺寸：18.0，
颜色：Colors.teal，
),
正文(
“$\u日期”，
样式：TextStyle(
颜色：Colors.teal，
fontWeight:fontWeight.bold，
字体大小：18.0），
),
],
),
)
],
),
正文(
“改变”，
样式：TextStyle(
颜色：Colors.teal，
fontWeight:fontWeight.bold，
字体大小：18.0），
),
],
),
),
颜色：颜色，白色，
),
TextFormField(
键盘类型：TextInputType.phone，
自动更正：错误，
验证器：（值）{
if（value.isEmpty | | value.length<10）{
返回“请输入有效数字”；
}
},
onSaved：（字符串值）{
data.days=数值；
},
maxLines:1，
装饰：输入装饰(
labelText:“输入您的号码”，
hintText:'输入一个数字'，
图标：常量图标（Icons.phone），
标签样式：
TextStyle（decorationStyle:TextDecorationStyle.solid）），
),
],
),
)),
台阶(
提尔
flutter_datetime_picker:
git:
url: https://github.com/derohimat/flutter_datetime_picker.git
@override
Widget build(BuildContext context) {
steps = [
Step(
import 'package:flutter/material.dart';
import 'package:flutter_datetime_picker/flutter_datetime_picker.dart';
class MyData {
String title;
String days;
String words;
String rep;
MyData({this.title, this.days, this.words, this.rep});
}
class StepperBody extends StatefulWidget {
@override
_StepperBodyState createState() => _StepperBodyState();
}
class _StepperBodyState extends State<StepperBody> {
String _date = "Not set";
int currStep = 0;
static var _focusNode = FocusNode();
GlobalKey<FormState> _formKey = GlobalKey<FormState>();
static MyData data = MyData();
List<GlobalKey<FormState>> formKeys = [
GlobalKey<FormState>(),
GlobalKey<FormState>(),
GlobalKey<FormState>(),
GlobalKey<FormState>()
];
List<Step> steps = [];
@override
void initState() {
super.initState();
_focusNode.addListener(() {
setState(() {});
print('Has focus: $_focusNode.hasFocus');
});
}
@override
Widget build(BuildContext context) {
steps = [
Step(
title: const Text(
'Name',
style: TextStyle(
fontFamily: 'Maax',
fontSize: 20,
),
),
//subtitle: const Text('Enter your name'),
isActive: true,
//state: StepState.error,
state: StepState.indexed,
content: Form(
key: formKeys[0],
child: Column(
children: <Widget>[
TextFormField(
style: TextStyle(
fontFamily: 'Maax',
fontWeight: FontWeight.w500,
),
focusNode: _focusNode,
keyboardType: TextInputType.text,
autocorrect: false,
onSaved: (String value) {
data.title = value;
},
maxLines: 1,
//initialValue: 'Aseem Wangoo',
validator: (value) {
if (value.isEmpty || value.length < 1) {
return 'Please enter title';
}
},
decoration: InputDecoration(
labelText: 'What is the name of the test?',
hintText: 'Enter a name',
//filled: true,
icon: Icon(Icons.add),
labelStyle: TextStyle(
decorationStyle: TextDecorationStyle.solid,
fontFamily: 'Maax',
fontWeight: FontWeight.w500)),
),
],
),
)),
Step(
title: const Text('Date'),
//subtitle: const Text('Subtitle'),
isActive: true,
//state: StepState.editing,
state: StepState.indexed,
content: Form(
key: formKeys[1],
child: Column(
children: <Widget>[
RaisedButton(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(5.0)),
elevation: 4.0,
onPressed: () {
DatePicker.showDatePicker(context,
theme: DatePickerTheme(
containerHeight: 210.0,
),
showTitleActions: true,
minTime: DateTime(2000, 1, 1),
maxTime: DateTime(2022, 12, 31), onConfirm: (date) {
print('confirm $date');
_date = '${date.year} - ${date.month} - ${date.day}';
print('date ${_date}');
setState(() {});
}, currentTime: DateTime.now(), locale: LocaleType.en);
},
child: Container(
alignment: Alignment.center,
height: 50.0,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
children: <Widget>[
Container(
child: Row(
children: <Widget>[
Icon(
Icons.date_range,
size: 18.0,
color: Colors.teal,
),
Text(
" $_date",
style: TextStyle(
color: Colors.teal,
fontWeight: FontWeight.bold,
fontSize: 18.0),
),
],
),
)
],
),
Text(
" Change",
style: TextStyle(
color: Colors.teal,
fontWeight: FontWeight.bold,
fontSize: 18.0),
),
],
),
),
color: Colors.white,
),
TextFormField(
keyboardType: TextInputType.phone,
autocorrect: false,
validator: (value) {
if (value.isEmpty || value.length < 10) {
return 'Please enter valid number';
}
},
onSaved: (String value) {
data.days = value;
},
maxLines: 1,
decoration: InputDecoration(
labelText: 'Enter your number',
hintText: 'Enter a number',
icon: const Icon(Icons.phone),
labelStyle: TextStyle(
decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Email'),
// subtitle: const Text('Subtitle'),
isActive: true,
state: StepState.indexed,
// state: StepState.disabled,
content: Form(
key: formKeys[2],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.emailAddress,
autocorrect: false,
validator: (value) {
if (value.isEmpty || !value.contains('@')) {
return 'Please enter valid email';
}
},
onSaved: (String value) {
data.words = value;
},
maxLines: 1,
decoration: InputDecoration(
labelText: 'Enter your email',
hintText: 'Enter a email address',
icon: const Icon(Icons.email),
labelStyle: TextStyle(
decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Age'),
// subtitle: const Text('Subtitle'),
isActive: true,
state: StepState.indexed,
content: Form(
key: formKeys[3],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.number,
autocorrect: false,
validator: (value) {
if (value.isEmpty || value.length > 2) {
return 'Please enter valid age';
}
},
maxLines: 1,
onSaved: (String value) {
data.rep = value;
},
decoration: InputDecoration(
labelText: 'Enter your age',
hintText: 'Enter age',
icon: const Icon(Icons.explicit),
labelStyle: TextStyle(
decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
// Step(
// title: const Text('Fifth Step'),
// subtitle: const Text('Subtitle'),
// isActive: true,
// state: StepState.complete,
// content: const Text('Enjoy Step Fifth'))
];
void showSnackBarMessage(String message,
[MaterialColor color = Colors.red]) {
Scaffold.of(context).showSnackBar(SnackBar(content: Text(message)));
}
void _submitDetails() {
final FormState formState = _formKey.currentState;
if (!formState.validate()) {
showSnackBarMessage('Please enter correct data');
} else {
formState.save();
print("Name: ${data.title}");
print("Phone: ${data.days}");
print("Email: ${data.words}");
print("Age: ${data.rep}");
showDialog(
context: context,
child: AlertDialog(
title: Text("Details"),
//content: Text("Hello World"),
content: SingleChildScrollView(
child: ListBody(
children: <Widget>[
Text("Name : " + data.title),
Text("Phone : " + data.days),
Text("Email : " + data.words),
Text("Age : " + data.rep),
],
),
),
actions: <Widget>[
FlatButton(
child: Text('OK'),
onPressed: () {
Navigator.of(context).pop();
},
),
],
));
}
}
return Container(
child: Form(
key: _formKey,
child: ListView(children: <Widget>[
Stepper(
steps: steps,
type: StepperType.vertical,
currentStep: this.currStep,
onStepContinue: () {
setState(() {
if (formKeys[currStep].currentState.validate()) {
if (currStep < steps.length - 1) {
currStep = currStep + 1;
} else {
currStep = 0;
}
}
// else {
// Scaffold
// .of(context)
// .showSnackBar( SnackBar(content: Text('$currStep')));
// if (currStep == 1) {
// print('First Step');
// print('object' + FocusScope.of(context).toStringDeep());
// }
// }
});
},
onStepCancel: () {
setState(() {
if (currStep > 0) {
currStep = currStep - 1;
} else {
currStep = 0;
}
});
},
onStepTapped: (step) {
setState(() {
currStep = step;
});
},
),
RaisedButton(
child: Text(
'Save details',
style: TextStyle(color: Colors.white),
),
onPressed: _submitDetails,
color: Colors.blue,
),
]),
));
}
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: "test",),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(child: StepperBody()),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}