我有一个带有 Text 小部件的按钮，在一个 showModalBottomSheet 内，它构建了另一个 showModalBottomSheet，其中包含一个 cupertinoPicker。如何返回 cupertinopicker 的值？它仅在我关闭第一个底页时返回值！而不是在 cupertinoPicker(bottomsheet) 被解雇时这样做！谢谢你们
这是我的鳕鱼
FlatButton(
color: Colors.white,
onPressed: () => showModalBottomSheet<dynamic>(
isScrollControlled: true,
context: context,
builder: (BuildContext context) => Container(
child: Container(
color: Colors.black45,
child: SingleChildScrollView(
child: Column(
children: <Widget>[
Row(
children: <Widget>[
Padding(
padding:
const EdgeInsets.only(
top: 50.0,
left: 120),
child: Text(
'Gå med',
style: TextStyle(
fontSize: 34,
color:
Colors.white),
),
),
SizedBox(
width: 40,
),
FlatButton(
onPressed: () =>
Navigator.pop(
context),
child: Icon(
Icons.clear,
color: Colors.white,
),
)
],
),
Form(
key: _formKey,
child: Column(
mainAxisSize:
MainAxisSize.min,
children: <Widget>[
Padding(
padding: EdgeInsets
.symmetric(
horizontal:
30.0,
vertical: 5.0),
child: TextFormField(
decoration: InputDecoration(
labelText:
'Restaurangens namn',
labelStyle: TextStyle(
fontWeight:
FontWeight
.bold)),
validator: (input) =>
input
.trim()
.isEmpty
? 'please enter a valid name'
: null,
onSaved: (input) =>
_name = input,
),
),
Padding(
padding: EdgeInsets
.symmetric(
horizontal:
30.0,
vertical: 5.0),
child: TextFormField(
decoration: InputDecoration(
labelText:
'Email',
labelStyle: TextStyle(
fontWeight:
FontWeight
.bold)),
validator: (input) =>
!input.contains(
'@')
? 'please enter a valid email'
: null,
onSaved: (input) =>
_email = input,
),
),
Padding(
padding:
const EdgeInsets
.only(
left: 30.0,
right: 0.0),
child: Row(
children: <Widget>[
SizedBox(
width: 200,
child:
TextFormField(
decoration: InputDecoration(
labelText:
'Telefon nummer',
labelStyle: TextStyle(
fontWeight:
FontWeight.bold)),
keyboardType:
TextInputType
.phone,
validator: (input) => input
.trim()
.isEmpty
? 'please enter a valid phone Number'
: null,
onChanged:
(input) =>
tel =
input,
),
),
],
),
),
Padding(
padding:
const EdgeInsets
.only(
left: 30.0,
right: 0.0),
child: Row(
children: <Widget>[
SizedBox(
width: 200,
),
Padding(
padding:
const EdgeInsets
.only(
top: 50.0,
left: 0),
child:
CupertinoButton(
child: Text(citys[selectedcity]),
onPressed: () =>
showModalBottomSheet(
context:
context,
builder: (BuildContext
context) =>
Container(
color: Colors
.white,
height: 200,
width: MediaQuery.of(
context)
.size
.width,
child:
CupertinoPicker(
onSelectedItemChanged:
(int
index) {
setState(
() {
selectedcity = index;
print(citys[selectedcity]);
});
},
itemExtent:
30,
children: List<
Widget>.generate(
citys
.length,
(index) {
return Center(
child:
Text(citys[index]),
);
}),
),
),
)
)
)],
),
),
Padding(
padding: EdgeInsets
.symmetric(
horizontal:
30.0,
vertical: 5.0),
child: TextFormField(
controller: _pass,
decoration: InputDecoration(
labelText:
'Lösenord',
labelStyle: TextStyle(
fontWeight:
FontWeight
.bold)),
validator: (input) =>
input.length < 6
? 'must contain at least 6 characters'
: null,
onSaved: (input) =>
_password = input,
obscureText: true,
),
),
Padding(
padding: EdgeInsets
.symmetric(
horizontal:
30.0,
vertical: 0.0),
child: TextFormField(
controller:
_confirmPass,
decoration: InputDecoration(
labelText:
'Lösernord igen',
labelStyle: TextStyle(
fontWeight:
FontWeight
.bold)),
validator: (val) {
if (val !=
_pass.text) ;
return 'Not Match';
},
onSaved: (input) =>
_password = input,
obscureText: true,
),
),
SizedBox(
height: 20,
),
Container(
width: 140,
child: OutlineButton(
onPressed: _submit,
color: Colors.black,
padding:
EdgeInsets.all(
5.0),
child: Text(
'Gå med',
style: TextStyle(
color: Colors
.white,
fontSize: 18.0),
),
),
),
SizedBox(
width: 20,
),
],
),
),
],
),
),
),
),
),
child: Text(
' Registera',
style: TextStyle(
color: Colors.black, fontSize: 18.0),
))