The named parameter 'onTap' isn't defined - flutter

I currently learning Flutter and I'm very new to it. in my app I used responsive grid package and add Text in responsive container. i wanted to go to another page when tap on this text but my bad it gives me this error.
The named parameter 'onTap' isn't defined.
Try correcting the name to an existing named parameter's name, or defining a named parameter with the name 'onTap'.
i used following code:
Widget build(BuildContext context) {
return Scaffold(
body: SingleChildScrollView(
child: Container(
child: ResponsiveGridRow(children: [
ResponsiveGridCol(
lg: 12,
child: Container(
height: 400,
alignment: Alignment.center,
color: Colors.orange,
child: Column(
children: [
Container(
margin: EdgeInsets.only(top: 150),
alignment: Alignment.center,
child: Text("Welcome To",
style: TextStyle(
fontSize: 40,
color: Colors.white)),
),
Container(
alignment: Alignment.center,
child: Text("our App",
style: TextStyle(
fontSize: 40,
color: Colors.white,
fontWeight: FontWeight.bold)),
),
],
),
),
),
ResponsiveGridCol(
xs: 4,
md: 2,
child: Container(
height: 18,
alignment: Alignment.centerLeft,
child: Text("Login",
style: TextStyle(
fontSize: 13,
// decoration: TextDecoration.underline,
color: Colors.orange[800])),
onTap: () { // i got error here
Navigator.push(
context,
MaterialPageRoute(builder: (context) => SignIn()),
);
}
),
)
]),
),
),
);
}
}

Your widget does not have an onTap property you need to create as show below by wrapping the widget that you need to be clickable with a gesture detector or InkWell
GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => SignIn()),
);
}
child:Container(
height: 18,
alignment: Alignment.centerLeft,
child: Text("Login",
style: TextStyle(
fontSize: 13,
// decoration: TextDecoration.underline,
color: Colors.orange[800])),
)),

The Container widget does not have onTap property try to wrap it in InkWell like this:
InkWell(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => SignIn()),
);
},
child: Container(
height: 18,
alignment: Alignment.centerLeft,
child: Text("Login",
style: TextStyle(
fontSize: 13,
// decoration: TextDecoration.underline,
color: Colors.orange[800])),
)))

Related

flutter how to floatingactionbutton overlapping alertdialog?

I want to floating action button is front of the alert dialog, I tried add elevation to floatingactionbutton and alertdialog but still not working. is it possible to make floatingactionbutton overlapping all layout including alertdialog?
this my alertdialog using lib rflutter_alert
var alertStyle = AlertStyle(
// animationType: AnimationType.fromTop,
alertElevation: 1,
isCloseButton: false,
isOverlayTapDismiss: false,
descStyle: TextStyle(fontSize: textBody3),
descTextAlign: TextAlign.center,
titleStyle: TextStyle(
color: Colors.red,
fontSize: textHeader1,
fontWeight: FontWeight.bold),
alertAlignment: Alignment.center,
);
Alert(
context: context,
style: alertStyle,
content: Column(
children: <Widget>[
const SizedBox(
height: 30,
),
Text(msg),
const SizedBox(
height: 30,
),
Text(jam)
],
),
buttons: [
DialogButton(
child: Text(
"OK",
style: TextStyle(color: Colors.white, fontSize: textButton1),
),
onPressed: () => Navigator.pop(context),
color: Palette.color_primary,
radius: BorderRadius.circular(0.0),
),
],
image: flag == "OK"
? Image.asset(
"assets/images/success.png",
height: 50,
width: 50,
)
: Image.asset(
"assets/images/error.png",
height: 50,
width: 50,
),
).show();
and this the floatingactionbutton using lib DraggableFab
#override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButton: DraggableFab(
child: FloatingActionButton.extended(
elevation: 10,
onPressed: () {
getLocation();
},
label:ValueListenableBuilder(
valueListenable: notifierLocFab,
builder: (BuildContext context, bool value,Widget? child) {
return Column(
children: [
Text(latitudeFab.toStringAsFixed(7)),
Text(longitudeFab.toStringAsFixed(7)),
],
);
}),
),
),
);
}

How to fix a non-null String must be provided to a Text widget

this is part of my code, I keep getting a non-null String must be provided to a Text widget.
Still new to flutter, so I'm not sure on how to fix this. I tried putting the ??"" on child: Text(myQuiz[0][i.toString()] but then it gave me an error on The method '[]' was called on null.
Receiver: null
Tried calling:
Widget optionButton(String k) {
return Padding(
padding: EdgeInsets.only(
top: 10
),
child: MaterialButton(
onPressed: () => checkAns(k),
child: Text(
myQuiz[1][i.toString()][k],
style: TextStyle(
color: Colors.black,
fontFamily: "Open Sans",
fontSize: 16.0,
),
maxLines: 1,
),
color: buttonColor[k],
minWidth: 200.0,
height: 45.0,
shape:
RoundedRectangleBorder(borderRadius: BorderRadius.circular(18.0),
side: BorderSide(color: Color(0xffb0dab9))),
),
);
}
#override
Widget build(BuildContext context) {
SystemChrome.setPreferredOrientations(
[DeviceOrientation.portraitDown, DeviceOrientation.portraitUp]);
return WillPopScope(
onWillPop: () {
return showDialog(
context: context,
builder: (context) => AlertDialog(
content: Text("You must finish this quiz :)"),
actions: <Widget>[
FlatButton(
onPressed: () {
Navigator.of(context).pop();
},
child: Text(
'Ok',
),
)
],
));
},
child: Scaffold(
appBar: AppBar(title: Text('Quiz'),backgroundColor: Color(0xffb0dab9)),
backgroundColor: Colors.yellow[100],
body: Container(
padding: EdgeInsets.all(50),
child: SingleChildScrollView(
child: Column(
children: <Widget>[
Container(
padding: EdgeInsets.all(20),
alignment: Alignment.center,
child: Text(myQuiz[0][i.toString()],
style: TextStyle(fontSize: 20.0, color: Colors.black),
),
),
AbsorbPointer(
absorbing: disableAnswer,
child: Container(
padding: EdgeInsets.only(top: 30),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
optionButton('a'),
optionButton('b'),
optionButton('c'),
optionButton('d'),
],
),
),
),
Container(
padding: EdgeInsets.only(top: 30),
alignment: Alignment.topCenter,
child: Center(
child: Text(
showTimer ,
style: TextStyle(
fontSize: 20.0,
),
),
),
),
],
),
),
),
)
);
}
}
It is because a null value is being provide to your Text widget
From your code.. one or more of the following is null and not a string
myQuiz[1][i.toString()][k]
showTimer
Try
...
#override
Widget build(BuildContext context) {
print(myQuiz[1][i.toString()][k]);
print(showTimer);
to find out which is the null value
Try this.
Text(
myQuiz[1]?[i?.toString()]?[k] ?? "Default Value",
style: TextStyle(
color: Colors.black,
fontFamily: "Open Sans",
fontSize: 16.0,
),
maxLines: 1,
),
Thanks for helping, I have found the answer, it was in the getRandom, as the json does not have a 0, so when the quiz runs and hit 0, it causes the error

Flutter: How can i put Textfield input into a list to build a ListView.builder

Im trying to build a listviewbuilder since a few days. For that i need the textfield input from another screen. I looked a lot of tutorials and question but it doesnt work.Im trying to put the input from multiple textfields into multiple lists to build a Listview builder. It would be the best if i can save all Textfield input when i press on flatbutton. I hope someone can help me.
First page
List<String> time = ["8:00"];List<String>
List<String> where = ["Am See"];
List<String> who = ["Eric"];
List<String> when = ["Donnerstag 21.4.21"];
body: SingleChildScrollView(
physics: ScrollPhysics(),
child: Column(children: [
Upperscreen(size: size),
ListView.builder(
physics: NeverScrollableScrollPhysics(),
shrinkWrap: true,
itemCount: where.length,
itemBuilder: (BuildContext context, int Index) {
return Column(children: [
SizedBox(
height: 40,
),
Container(
child: GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => Meet1()));
},
child: Container(
width: size.width * 0.9,
decoration: BoxDecoration(
borderRadius: BorderRadius.all(
Radius.circular(70)),
gradient: LinearGradient(
begin: Alignment.topRight,
end: Alignment.bottomRight,
colors: [
Colors.green,
Colors.orange,
],
),
),
child: Column(children: <Widget>[
SizedBox(
height: 10,
),
Padding(
padding: EdgeInsets.all(20),
child: Column(
children: <Widget>[
Text(
time[Index],
style: TextStyle(
color: Colors.white,
fontSize: 40,
fontWeight:
FontWeight.bold),
),
SizedBox(
height: 10,
),
Text(
who[Index],
style: TextStyle(
color: Colors.white,
fontSize: 20,
fontWeight:
FontWeight.bold),
),
Text(
when[Index],
style: TextStyle(
color: Colors.white,
fontSize: 20,
fontWeight:
FontWeight.bold),
),
Text(
where[Index],
style: TextStyle(
color: Colors.white,
fontSize: 20,
fontWeight:
FontWeight.bold),
Second page
child: Column(children: <Widget>[
SizedBox(
height: 10,
),
Padding(
padding: EdgeInsets.all(20),
child: Column(
children: <Widget>[
TextField(decoration: InputDecoration(hintText: " Time ")),
SizedBox(
height: 10,
),
TextField(
decoration: InputDecoration(hintText: " Who "),
),
SizedBox(
height: 10,
),
TextField(
decoration: InputDecoration(hintText: " Date "),
),
SizedBox(
height: 10,
),
TextField(
decoration: InputDecoration(hintText: " Where "),
),
SizedBox(height: 10)
],
),
),
]));
Here the Flatbutton to add all.
return FlatButton(
child: Icon(
Icons.check_circle_outline_rounded,
color: Colors.green,
size: 120,
),
onPressed: () {
Navigator.of(context).popUntil((route) => route.isFirst);
},
Use a TextEditingController(), just like this -
TextEditingController() myController = TextEditingController();
Then assign this controller to controller property in TextField() -
TextField(
controller: myController,
),
Then use myController.text to retrieve the text from TextField(), and pass it to other pages as a String parameter -
Example -
class Screen1 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
//....
body: FlatButton(
child: Icon(
Icons.check_circle_outline_rounded,
color: Colors.green,
size: 120,
),
onPressed: () {
Navigator.push(context, MaterialPageRoute(builder: (builder) {
return Screen2(text: myController.text);
}));
},
//....
),
);
}
}
Second Page -
class Screen2 extends StatelessWidget {
String text;
Screen2({this.text});
#override
Widget build(BuildContext context) {
return Scaffold(
//....
body: Text(text),
);
}
}
Go to this link to see another example
Now, here I used only 1 parameter "text". You can use multiple parameters like - "text1", "text2", "text3" and so on, as per your requirement, and use as many TextEditingController() for this.
*****Also Note that use of FlatButton() is depreciated, you can use a TextButton() instead

Rounded AppBar in Flutter with Back button

I created a custom rounded AppBar using a code found here, but with just a title in the center.
I wanted to add a backbutton in the top left corner inside AppBar and I tried nesting a button and the text in a Row, but the result is that neither the button or the text are shown. Any help?
Here the code:
import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
// ignore: must_be_immutable
class RoundedAppBar extends StatelessWidget implements PreferredSizeWidget {
String title;
RoundedAppBar(this.title);
#override
Widget build(BuildContext context) {
return PreferredSize(
child: LayoutBuilder(builder: (context, constraints) {
final width =
constraints.maxWidth * 16; //per modificare "rotondità" app Bar
return OverflowBox(
maxHeight: double.infinity,
maxWidth: double.infinity,
child: SizedBox(
height: width,
width: width,
child: Padding(
padding: EdgeInsets.only(
bottom: width / 2 - preferredSize.height / 2),
child: Container(
alignment: Alignment.bottomCenter,
padding: EdgeInsets.only(bottom: 10),
decoration: BoxDecoration(
color: const Color(0xff000350),
shape: BoxShape.circle,
),
child: Row(
children: [
Align(
alignment: Alignment.centerLeft,
child: IconButton(
color: Colors.black,
icon: Icon(Icons.chevron_left),
onPressed: () => Navigator.pop(context),
),
),
Text(
title,
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: 'Conformity',
color: Colors.white,
fontSize: 30,
fontWeight: FontWeight.normal),
),
],
)),
),
),
);
}),
preferredSize: preferredSize);
}
#override
Size get preferredSize => Size.fromHeight(80);
EDIT:
Tried using ListTile as suggested, something happened but didn't work properly.
Here the result.
child: ListTile(
title: Text(
title,
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: 'Conformity',
color: Colors.white,
fontSize: 30,
fontWeight: FontWeight.normal),
),
leading: IconButton(
color: Colors.white,
icon: Icon(Icons.chevron_left),
onPressed: () => Navigator.pop(context),
),
),
EDIT:
I inserted your code as shown. With trial and error, using 35 as height I was able to see the title, but still no button.
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
_buildBack(true, context),
Container(
height: 35,
child: Text(
title,
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: 'Conformity',
color: Colors.white,
fontSize: 30,
fontWeight: FontWeight.normal),
),
),
_buildBack(false, context),
],
and
Widget _buildBack(bool isPlaceHolder, BuildContext context) {
return Visibility(
child: InkWell(
child: Icon(
Icons.close,
size: 35,
),
onTap: () => Navigator.of(context, rootNavigator: true).pop('dialog'),
),
maintainSize: true,
maintainAnimation: true,
maintainState: true,
visible: !isPlaceHolder,
);
}
and here the result
You can use a ListTile and use a IconButton as leading.
ListTile(
leading: IconButton(
icon: Icon(Icons.back),
title: '',
onPressed => Navigator.pop(context),
),
),
Another possibility I see:
As the child from the AppBar
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
_buildBack(true, context),
Container(
height: height,
child: Text(
'$_title',
style: Theme.of(context).textTheme.headline2,
),
),
_buildBack(false, context),
],
),
In another place outside the builder.
Widget _buildBack(bool isPlaceHolder, Buildcontext context) {
return Visibility(
child: InkWell(
child: Icon(
Icons.close,
size: widget.height,
),
onTap: () => Navigator.of(context, rootNavigator: true).pop('dialog'),
),
maintainSize: true,
maintainAnimation: true,
maintainState: true,
visible: !isPlaceHolder,
);
}}
Here there is again a row as you have tried it yourself, but this one is set up a little differently and an iconButton is built before and after the text, but so that the text remains in the center, the second one is made invisible,

when i tried to calling a dialog it will show me this error setState() or markNeedsBuild called during build

This is my dialog Code
Here is am getting an error of setstate() or MarkerneedsBuild called during the build. this overlay widget cannot be marked as needing to process of building widgets.
When I am trying to call _onAlertOtp widget it will show me this error.in the build method, i've bloc and state when my signup is successful then i have to call alert dialog. but when I am trying to do that it will show me the error. Hope you understand the question please help me.
_onAlertotp(BuildContext context) {
return showDialog<void>(
context: context,
barrierDismissible: false, // user must tap button!
builder: (BuildContext context) {
return AlertDialog(
title: Text('Enter OTP'),
content: SingleChildScrollView(
child: ListBody(
children: <Widget>[
Container(
height: MediaQuery.of(context).size.height / 2.7,
width: MediaQuery.of(context).size.width,
alignment: Alignment.center,
child: ListView(
children: <Widget>[
Padding(
padding: const EdgeInsets.symmetric(vertical: 8.0),
child: Text(
'We have Texted and/or Emailed OTP (One Time Pin) to your registered cell phone and/ or email account. Please check and enter OTP below to activate your TUDO account.',
style: TextStyle(
fontWeight: FontWeight.bold, fontSize: 15),
textAlign: TextAlign.center,
),
),
SizedBox(
height: 5,
),
Padding(
padding: const EdgeInsets.symmetric(
vertical: 8.0, horizontal: 30),
child: PinCodeTextField(
length: 6, // must be greater than 0
obsecureText: false, //optional, default is false
shape: PinCodeFieldShape
.underline, //optional, default is underline
onDone: (String value) {
setState(() {
passcode = value;
print(value);
});
},
textStyle: TextStyle(
fontWeight: FontWeight
.bold), //optinal, default is TextStyle(fontSize: 18, color: Colors.black, fontWeight: FontWeight.bold)
onErrorCheck: (bool value) {
setState(() {
hasError = value;
});
},
shouldTriggerFucntions:
changeNotifier.stream.asBroadcastStream(),
),
),
Padding(
padding: const EdgeInsets.symmetric(horizontal: 30.0),
child: Text(
hasError
? "*Please fill up all the cells and press VERIFY again"
: "",
style: TextStyle(
color: Colors.red.shade300, fontSize: 12),
),
),
SizedBox(
height: 20,
),
RichText(
textAlign: TextAlign.center,
text: TextSpan(
text: "Didn't receive the code? ",
style:
TextStyle(color: Colors.black54, fontSize: 15),
children: [
TextSpan(
text: " RESEND",
// recognizer: onTapRecognizer,
style: TextStyle(
color: colorStyles["primary"],
fontWeight: FontWeight.bold,
fontSize: 16))
]),
),
SizedBox(
height: 7,
),
Container(
margin: const EdgeInsets.symmetric(
vertical: 16.0, horizontal: 30),
child: ButtonTheme(
height: 50,
child: FlatButton(
onPressed: () async {
/// check the [_onData] fucntion to understand better
changeNotifier.add(Functions.submit);
// at first we will check error on the press of the button.
if (!hasError) {
_onAlertrunnigbusiness(context);
}
},
child: Center(
child: Text(
"VERIFY".toUpperCase(),
style: TextStyle(
color: Colors.white,
fontSize: 18,
fontWeight: FontWeight.bold),
)),
),
),
decoration: BoxDecoration(
color: colorStyles["primary"],
borderRadius: BorderRadius.circular(5),
),
),
],
),
),
],
),
),
actions: <Widget>[
FlatButton(
child: Text('Regret'),
onPressed: () {
Navigator.of(context).pop();
},
),
],
);
},
);
}
Here Is Another DIalog. which open on first dialog verify button click
_onAlertrunnigbusiness(context) {
return showDialog<void>(
context: context,
barrierDismissible: false, // user must tap button!
builder: (BuildContext context) {
return AlertDialog(
title: Text('Are you running Business?'),
content: Container(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
SizedBox(
height: 10,
),
Text(
"TUDO.App aims at Businesses bridging gaps between Business Service Providers and Consumers collaborate on unique technology platform. If you own a business, we strongly recommend, provide your business information to grow your customer base and expand your business services. Any questions? Call us #1-800-888-TUDO"),
SizedBox(
height: 10,
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
FlatButton.icon(
icon: Icon(FontAwesomeIcons.arrowCircleRight),
label: Text('No'),
color: colorStyles["primary"],
textColor: Colors.white,
padding:
EdgeInsets.symmetric(vertical: 10, horizontal: 15),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(7),
),
onPressed: () {
NavigationHelper.navigatetoMainscreen(context);
},
),
SizedBox(height: 10),
FlatButton.icon(
icon: Icon(FontAwesomeIcons.arrowCircleRight),
label: Text('Yes'),
color: colorStyles["primary"],
textColor: Colors.white,
padding:
EdgeInsets.symmetric(vertical: 10, horizontal: 15),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(7),
),
onPressed: () {
NavigationHelper.navigatetoBspsignupcreen(context);
},
),
],
)
],
),
),
actions: <Widget>[
FlatButton(
child: Text('Close'),
onPressed: () {
Navigator.of(context).pop();
},
),
],
);
},
);
}
And Here i am calling my dialog
#override
Widget build(BuildContext context) {
return BlocListener<SignupBloc, SignupState>(
bloc: widget._signupBloc,
listener: (
BuildContext context,
SignupState currentState,
) {
if (currentState is InSignupState) {
_countries = currentState.countries.countries;
return Container(child: content(_signupBloc, context, _countries));
}
if (currentState is SignupButtonClickedEvent) {
print('SignupButtonClickedEvent clicked');
return Container();
}
if (currentState is SignupSuccessState) {
print(
' You are awesome. you have successfully registered without confirmation');
print(currentState.signupUser.toJson());
print("Hey Otp Is opned");
if (!_isError) {
return _onAlertotp(context);
}
// NavigationHelper.navigatetoMainscreen(context);
_isLoading = false;
showAlertBox = true;
return Container(
child: content(_signupBloc, context, _countries),
);
}
if (currentState is SignupVerficationOtp) {
print('signup verficitaion otp button clicked');
return Container();
}
return Container(child: content(_signupBloc, context, _countries));
},
);
}
}
try using below code to display an alert dialog
in place of return _onAlertotp(context);
WidgetsBinding.instance.addPostFrameCallback((_) {
// show alert dialog here
_onAlertotp(context);
});
You should use a BlocListener at the root of your build method to handle events that do not return a widget (in your case the showDialog method)
Your if (currentState is SignupSuccessState) { part would be in the BlocListener and not in the BlocBuilder