当我们点击手势检测器时，我试图将表单字段的值设置为“用户名”变量。 'username' 变量中的文本正在使用 Navigator.pop() 方法从 create_account.dart 传回函数 createUserInFirestore() 到 home.dart
我也附上代码供参考
这是我的 create_account.dart 文件
class CreateAccount extends StatefulWidget {
@override
_CreateAccountState createState() => _CreateAccountState();
}
class _CreateAccountState extends State<CreateAccount> {
final GlobalKey<FormState> _formkey =GlobalKey<FormState>();
String username="";
submit(){
_formkey.currentState.save();
Navigator.pop(context,username);
}
@override
Widget build(BuildContext parentContext) {
return Scaffold(
appBar: header(context,titleText: "Set up your profile"),
body: ListView(
children: <Widget>[
Container(
child:Column(
children:<Widget> [
Padding(
padding: EdgeInsets.only(top: 25.0),
child: Center(
child: Text("Create a username", style: TextStyle(fontSize: 25.0),),
),
),
Padding(padding: EdgeInsets.all(16.0),
child: Container(
child:Form(
key: _formkey,
child: TextFormField(
onSaved: (val)=>username=val,
decoration: InputDecoration(
border: OutlineInputBorder(),
labelText: "Username",
labelStyle: TextStyle(fontSize: 15.0),
hintText: "Must be at leat 3 characterstics",
),
),
),
),
),
GestureDetector(
onTap: submit(),
child: Container(
height:50.0 ,
width: 350.0,
decoration: BoxDecoration(
color: Colors.deepPurpleAccent,
borderRadius: BorderRadius.circular(7.0),
),
child: Center(
child:Text(
"Submit", style: TextStyle(
color: Colors.white,
fontSize: 15.0,
fontWeight: FontWeight.bold
),
),
),
),
)
],
) ,
)
],
),
);
}
}
还有 home.dart 文件
final GoogleSignIn googleSignIN = GoogleSignIn();
final DateTime timestamp= DateTime.now();
final userRef = FirebaseFirestore.instance.collection('users');
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
bool isAuth=false;
PageController pageController;
int pageIndex=0;
createUserInFirestore() async{
final GoogleSignInAccount user = googleSignIN.currentUser;
final DocumentSnapshot doc = await userRef.doc(user.id).get();
if(!doc.exists){
final username = await Navigator.push(context,MaterialPageRoute(builder: context)=>CreateAccount()));
userRef.doc(user.id).set({
"id": user.id,
"username":username,
"photoUrl":user.photoUrl,
"email":user.email,
"displayName": user.displayName,
"bio":"",
"timestamp":timestamp
});
}
}
@override
void initState(){
super.initState();
pageController= PageController();
googleSignIN.onCurrentUserChanged.listen((account) {
handleSignIn(account);
},onError: (err){
print('Enter signing in: $err');
});
googleSignIN.signInSilently(suppressErrors: false)
.then((account){
handleSignIn(account);
}).catchError((err){
print('Enter signing in: $err');
});
}
handleSignIn(GoogleSignInAccount account){
if(account!=null){
createUserInFirestore();
setState(() {
isAuth=true;
});
}else{
setState(() {
isAuth=false;
});
}
}
@override
void dispose(){
pageController.dispose();
super.dispose();
}
login(){
googleSignIN.signIn();
}
logout(){
googleSignIN.signOut();
}
onPageChanged(int pageIndex){
setState(() {
this.pageIndex=pageIndex;
});
}
onTap(int pageIndex){
pageController.animateToPage(
pageIndex,
duration: Duration(milliseconds: 300),
curve: Curves.easeInCirc
);
}
Scaffold buildAuthScreen(){
return Scaffold(
body: PageView(
children: <Widget>[
RaisedButton(
child: Text('Logout'),
onPressed: logout,
),
ActivityFeed(),
Upload(),
Search(),
Profile(),
],
controller: pageController,
onPageChanged: onPageChanged,
physics: NeverScrollableScrollPhysics(),
),
bottomNavigationBar: CupertinoTabBar(
currentIndex: pageIndex,
onTap: onTap,
activeColor:Theme.of(context).primaryColor,
items: [
BottomNavigationBarItem(icon: Icon(Icons.whatshot),),
BottomNavigationBarItem(icon: Icon(Icons.notifications_active),),
BottomNavigationBarItem(icon: Icon(Icons.photo_camera,size: 35.0,),),
BottomNavigationBarItem(icon: Icon(Icons.search),),
BottomNavigationBarItem(icon: Icon(Icons.account_circle),),
],
),
);
}
buildUnAuthScreen(){
return Scaffold(
body:Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topRight,
end: Alignment.bottomRight,
colors: [
Theme.of(context).primaryColor,
Theme.of(context).accentColor,
]
),
),
alignment: Alignment.center,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Text('LS App',
style: GoogleFonts.dellaRespira(fontSize: 50.0)
),
GestureDetector(
onTap: login,
child: Container(
width: 260.0,
height: 60.0,
decoration: BoxDecoration(
image:DecorationImage(
image: AssetImage('assets/images/google_signin_button.png'),
fit: BoxFit.cover
),
),
),
)
],
),
),
);
}
@override
Widget build(BuildContext context) {
return isAuth?buildAuthScreen():buildUnAuthScreen();
}
}
还有日志
======== Exception caught by widgets library =======================================================
The following NoSuchMethodError was thrown building CreateAccount(dirty, dependencies: [_LocalizationsScope-[GlobalKey#f10cd], _InheritedTheme], state: _CreateAccountState#4c9d8):
The method 'save' was called on null.
Receiver: null
Tried calling: save()
The relevant error-causing widget was:
CreateAccount file:///C:/Users/reddy/AndroidStudioProjects/ls_app/lib/pages/home.dart:36:91
When the exception was thrown, this was the stack:
#0 Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5)
#1 _CreateAccountState.submit (package:ls_app/pages/create_account.dart:16:27)
#2 _CreateAccountState.build (package:ls_app/pages/create_account.dart:52:26)
#3 StatefulElement.build (package:flutter/src/widgets/framework.dart:4612:27)
#4 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4495:15)
...
这是我得到的错误消息，如果您需要更多代码，请告诉我， 感谢您的帮助...！