Flutter RenderIndexedStack对象在布局期间被赋予了无限大小 [英] Flutter RenderIndexedStack object was given an infinite size during layout
问题描述
我正在解决此 DropDownItem 框错误，似乎一切正常，但是在加载时会弹出黄色边界.尝试了几件事，无法解决.我的 Widget 具有此代码.
I am battling this DropDownItem box error, everything seems to work, but pops up the yellow out of bounds while it loads. Tried several things and can not get it resolved. I have this code for my Widget.
@override
Widget build(BuildContext context) {
var _children = <Widget>[
!_createNew ? _referrerPractice() : _referrerCreate(),
];
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new Column(
mainAxisSize: MainAxisSize.max,
children: _children,
));
}
然后我将其用作功能之一.
I then use this as one of the functions.
Widget _referrerPractice() {
assert(!_createNew);
return new Form(
key: _formKey2,
child: new Expanded(
child: new ListView(
padding: const EdgeInsets.symmetric(horizontal: 16.0),
children: <Widget>[
new InputDecorator(
decoration: const InputDecoration(
labelText: 'Referrer Practice',
hintText: 'Choose Referrer Practice or choose new',
),
isEmpty: _referPractice == null,
child: new DropdownButton<String>(
value: _referPractice,
isDense: true,
onChanged: (String newValue) {
setState(() {
_referPractice = newValue;
});
},
items: practicelist.map((Map value) {
return new DropdownMenuItem<String>(
value: value['id'].toString(),
child: new Text(value['name']),
);
}).toList(),
),
),
new RaisedButton(
child: new Text('Start'), onPressed: _startReferrer),
],
),
),
);
}
似乎可以在另一页上使用，并且我不使用函数来填充窗口小部件，而只是使用常规的窗口小部件来填充窗口小部件，但是看起来应该与结构相同相同.
It seems to work on another page and I do not use a function to populate the widget, just a regular var of widgets, but seems it should be the same as the structure is the same.
有什么主意我想念的吗?这是一个 DropDownButton ，但是它发生在具有 DropDownButton 以及其他功能的结果页面上.
Any ideas what I am missing? This is one DropDownButton, but it happens on the resulting page that has a DropDownButton as well for the other function.
编辑**********这是工作代码
EDIT********** This is the working code
final List<String> _allTypeAppt = <String>['Elective OP', 'Hospital Transfer', 'Phone Consult'];
new Form(
key: _formKey,
autovalidate: _autovalidate,
onWillPop: _warnUserAboutInvalidData,
child: new Expanded(
child: new ListView(
padding: const EdgeInsets.symmetric(horizontal: 16.0),
children: <Widget>[
new TextFormField(
decoration: const InputDecoration(
icon: const Icon(Icons.person),
hintText: 'First Name?',
labelText: 'First Name *',
),
controller: _fnameController,
onSaved: (String value) { referral.fname = value; },
validator: _validateName,
),
new TextFormField(
decoration: const InputDecoration(
icon: const Icon(Icons.person),
hintText: 'Last Name?',
labelText: 'Last Name *',
),
controller: _lnameController,
onSaved: (String value) { referral.lname = value; },
validator: _validateName,
),
new _DateTimePicker(
labelText: 'DOB',
selectedDate: _fromDate,
selectDate: (DateTime date) {
setState(() {
_fromDate = date;
});
},
),
new TextFormField(
decoration: const InputDecoration(
icon: const Icon(Icons.phone),
hintText: 'How to contact?',
labelText: 'Phone Number *',
),
controller: _phoneController,
keyboardType: TextInputType.phone,
onSaved: (String value) { referral.contact = value; },
validator: _validatePhoneNumber,
// TextInputFormatters are applied in sequence.
/*inputFormatters: <TextInputFormatter> [
WhitelistingTextInputFormatter.digitsOnly,
// Fit the validating format.
_phoneNumberFormatter,
],*/
),
new TextFormField(
decoration: const InputDecoration(
icon: const Icon(Icons.phone),
hintText: 'Alt contact?',
labelText: 'Alt Phone Number *',
),
controller: _altPhoneController,
keyboardType: TextInputType.phone,
onSaved: (String value) { referral.altcontact = value; },
validator: _validatePhoneNumber,
// TextInputFormatters are applied in sequence.
/*inputFormatters: <TextInputFormatter> [
WhitelistingTextInputFormatter.digitsOnly,
// Fit the validating format.
_phoneNumberFormatter,
],*/
),
new TextFormField(
decoration: const InputDecoration(
icon: const Icon(Icons.email),
hintText: 'Patien Email?',
labelText: 'Patient Email *',
),
controller: _emailController,
onSaved: (String value) { referral.altcontact = value; },
//validator: _validatePhoneNumber,
// TextInputFormatters are applied in sequence.
/*inputFormatters: <TextInputFormatter> [
WhitelistingTextInputFormatter.digitsOnly,
// Fit the validating format.
_phoneNumberFormatter,
],*/
),
new TextFormField(
decoration: const InputDecoration(
hintText: 'Tell us about patient',
helperText: 'It does not have to be detailed yet',
labelText: 'Referral Details',
),
controller: _detailsController,
maxLines: 5,
),
new InputDecorator(
decoration: const InputDecoration(
labelText: 'Type of Appointment',
hintText: 'Choose an Appointment Type',
),
isEmpty: _typeAppt == null,
child: new DropdownButton<String>(
value: _typeAppt,
isDense: true,
onChanged: (String newValue) {
setState(() {
_typeAppt = newValue;
});
},
items: _allTypeAppt.map((String value) {
return new DropdownMenuItem<String>(
value: value,
child: new Text(value),
);
}).toList(),
),
),
new RaisedButton(
child: new Text('Submit Referral'),
onPressed: _submitData,
),
],
)
)
),
推荐答案
我能够重现您的问题，我不确定您为什么要以此方式构建布局.您正在将 DropDownButton 作为 InputDecorator 的 child 属性，这很好.但是，抛出此错误的原因是 DropDownMenuItem 溢出了 InputDecorator .换句话说，您不仅在 InputDecorator 中包含了 DopDownButton ，而且您的 items 都试图包含在与出色地.因此，Flutter对如何在 InputDecorator 提供的空间内放置项列表感到困惑.
I was able to reproduce your issue, I am not sure why are you building the layout this way. Your are feeding your DropDownButton as the child property for InputDecorator, which is fine. However, it is throwing this error because DropDownMenuItem is overflowing your InputDecorator. In other words, you are not only containing the DopDownButton within your InputDecorator, but also your items are trying to be contained in the same space as well. So, Flutter is confused on how to position the list of items inside the space provided by the InputDecorator.
我真的很困惑，您要尝试构建哪种布局，为什么需要使用 Form 和 InputDecorator ?
I am really confused what kind of layout you are trying to build, why do you need a Form and an InputDecorator for?
也许可以为您的设计选择提供一些背景信息，以便我们提供更好的帮助.
Maybe provide a little context to your design choices so that we can help better.
我用 Row 和 TextField 小部件创建了一个更简单的布局，这可能会有所帮助.
I have created a simpler layout with Row and TextField widgets, it might be of help.
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => new _MyAppState();
}
class _MyAppState extends State<MyApp> {
String _mySelection;
String _text = "Choose";
List<Map> _myJson = [
{"id": "ID 1310012", "name": "Newcommer"}, {"id": "ID 0000TEMP", "name": "Temp"}];
Widget _children() {
TextEditingController _controller = new TextEditingController(text: _text);
return new Expanded(child: new ListView(
padding: const EdgeInsets.symmetric(horizontal: 16.0),
children: <Widget>[
new Container (
child: new Row(
children: <Widget>[
new Expanded(
child: new TextField(
controller: _controller,
),
),
new DropdownButton(
isDense: true,
value: _mySelection,
items: _myJson.map((Map map) {
return new DropdownMenuItem<String>(
value: map["id"],
child: new Text(
map["name"],
),
);
}).toList(),
onChanged: (String newValue) {
setState(() {
_mySelection = newValue;
_text = newValue;
});
})
],),),
new RaisedButton(
child: new Text('Start'), onPressed: null),
]
));
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(title: new Text("Test")),
body: new Column(
mainAxisSize: MainAxisSize.max,
children: <Widget>[
_children(),
],
),
);
}
}
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