NavigationBar is imported from both 'package:flutter/src/material/navigation_bar.dart' and 'package:flutter_onboarding_slider/navigation_bar.dart' - flutter

Question

**i am facing error while running error is this because of packges or something else i have remove all the old code and add new still facing following error.
Error: 'NavigationBar' is imported from both 'package:flutter/src/material/navigation_bar.dart' and 'package:flutter_onboarding_slider/navigation_bar.dart'.
appBar: NavigationBar(
^^^^^^^^^^^^^
: Warning: Operand of null-aware operation '?.' has type 'GoogleMapController' which excludes null.
lib/…/map/map.dart:62
'GoogleMapController' is from 'package:google_maps_flutter/google_maps_flutter.dart' ('/D:/flutter/.pub-cache/hosted/pub.dartlang.org/google_maps_flutter-2.1.7/lib/google_maps_flutter.dart').
package:google_maps_flutter/google_maps_flutter.dart:1
_controller?.animateCamera(CameraUpdate.newCameraPosition(CameraPosition(
^
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_onboarding_slider/flutter_onboarding_slider.dart';
import 'package:fyppedometer/mainScreens/Navigation/navigationBar.dart';
import 'package:fyppedometer/widgets/constants.dart';
import 'package:fyppedometer/widgets/text.dart';
class MyHome extends StatefulWidget {
const MyHome({Key? key}) : super(key: key);
#override
State<MyHome> createState() => _MyHomeState();
}
class _MyHomeState extends State {
final Color kDarkBlueColor = Colors.cyan;
// ignore: non_constant_identifier_names
List<String> numbers_Height = [
for (var i = 1.1; i <= 10.0; i = i + 0.1) i.toString()
];
// ignore: non_constant_identifier_names
List<String> numbers_Weight = [for (var i = 1; i <= 1000; i++) i.toString()];
int _groupValue = -1;
String _selectedGender = 'male';
#override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
// color: Colors.amber,
child: OnBoardingSlider(
buttonText: 'Start',
onFinish: () {
Navigator.push(
context,
CupertinoPageRoute(
builder: (context) => Navbar(),
),
);
},
buttonTextColor: Colors.cyan,
// skipTextButton: Text(
// 'Skip',
// style: TextStyle(
// fontSize: 16,
// color: kDarkBlueColor,
// fontWeight: FontWeight.w600,
// ),
// ),
// trailing: Text(
// 'Login',
// style: TextStyle(
// fontSize: 16,
// color: kDarkBlueColor,
// fontWeight: FontWeight.w600,
// ),
// ),
// trailingFunction: () {
// // Navigator.push(
// // context,
// // CupertinoPageRoute(
// // builder: (context) => LoginPage(),
// // ),
// // );
// },
controllerColor: kDarkBlueColor,
totalPage: 3,
headerBackgroundColor: liteblue,
pageBackgroundColor: liteblue,
background: [
Padding(
padding: const EdgeInsets.only(top: 210, left: 80),
child: Image.asset(
'assets/gender.png',
height: MediaQuery.of(context).size.height * 0.6,
width: MediaQuery.of(context).size.width * 0.6,
),
),
Padding(
padding: const EdgeInsets.only(top: 160, left: 60),
child: Image.asset(
'assets/walking.png',
height: MediaQuery.of(context).size.height * 0.7,
width: MediaQuery.of(context).size.width * 0.7,
),
),
Padding(
padding: const EdgeInsets.only(top: 200, left: 60),
child: Image.asset(
'assets/human.png',
height: MediaQuery.of(context).size.height * 0.6,
width: MediaQuery.of(context).size.width * 0.6,
),
),
],
speed: 1.8,
pageBodies: [
Container(
// padding: EdgeInsets.symmetric(horizontal: 40),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
const Text(
'What’s Your Gender',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white,
fontSize: 24.0,
fontWeight: FontWeight.w600,
),
),
const SizedBox(
height: 10,
),
const Text(
'Calories & Stride length calculation need it ',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white60,
fontSize: 21.0,
fontWeight: FontWeight.w600,
),
),
const SizedBox(
height: 20,
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Container(
height: size.height * 0.1,
width: size.width * 0.5,
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(25), // radius of 10
color: Color.fromARGB(255, 19, 65, 103),
),
child: Center(
child: ListTile(
leading: Radio<String>(
activeColor: Colors.white,
value: 'male',
groupValue: _selectedGender,
onChanged: (value) {
setState(() {
_selectedGender = value!;
});
},
),
title: text(
textData: "Male",
color: Colors.white,
fontsize: 20.0,
fontweight: FontWeight.bold),
// Text(_selectedGender == 'male' ? 'Hello gentlement!' : 'Hi lady!')
),
),
),
SizedBox(height: 20),
Container(
height: size.height * 0.1,
width: size.width * 0.5,
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(25), // radius of 10
color: Color.fromARGB(255, 19, 65, 103),
),
child: Center(
child: ListTile(
leading: Radio<String>(
activeColor: Colors.white,
value: 'female',
groupValue: _selectedGender,
onChanged: (value) {
setState(() {
_selectedGender = value!;
});
},
),
title: text(
textData: "Female",
color: Colors.white,
fontsize: 20.0,
fontweight: FontWeight.bold),
// Text(_selectedGender == 'male' ? 'Hello gentlement!' : 'Hi lady!')
),
),
),
],
)
]),
),
Container(
// padding: EdgeInsets.symmetric(horizontal: 40),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
const Text(
'How Tall are you?',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white,
fontSize: 28.0,
fontWeight: FontWeight.w600,
),
),
const SizedBox(
height: 10,
),
const Text(
'To Personalize Your Fitness Goal ',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white60,
fontSize: 20.0,
fontWeight: FontWeight.w600,
),
),
const SizedBox(
height: 20,
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Center(
child: Container(
height: size.height * 0.10,
width: size.width * 0.5,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(15),
border: Border.all(
color: Color.fromARGB(255, 145, 174, 225))),
child: Center(
child: text(
textData: "Height",
fontsize: 30.0,
fontweight: FontWeight.bold,
color: Color.fromARGB(255, 147, 148, 152)),
),
),
),
SizedBox(
height: 30,
),
Center(
child: Container(
height: size.height * 0.13,
width: size.width * 0.5,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(20),
border: Border.all(
color: Color.fromARGB(255, 92, 89, 89)),
// color: Colors.white,
),
child: ListWheelScrollView.useDelegate(
itemExtent: 100,
// controller: fixedExtentScrollController,
physics: FixedExtentScrollPhysics(),
onSelectedItemChanged: (i) {
print(numbers_Height[i]);
},
childDelegate: ListWheelChildLoopingListDelegate(
children: <Widget>[
...numbers_Height.map((String number) {
return Center(
child: Text(
number,
style: const TextStyle(
fontSize: 28.0,
color: Colors.white,
fontWeight: FontWeight.bold,
fontStyle: FontStyle.normal,
decoration: TextDecoration.none),
),
);
})
],
),
),
),
)
],
)
]),
),
Container(
// padding: EdgeInsets.symmetric(horizontal: 40),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
const Text(
'How much do you Weight?',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white,
fontSize: 28.0,
fontWeight: FontWeight.w600,
),
),
const SizedBox(
height: 10,
),
const Text(
'To Personalize Your Fitness Goal ',
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.white60,
fontSize: 20.0,
fontWeight: FontWeight.w600,
),
),
const SizedBox(
height: 20,
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Center(
child: Container(
height: size.height * 0.10,
width: size.width * 0.5,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(15),
border: Border.all(
color: Color.fromARGB(255, 145, 174, 225))),
child: Center(
child: text(
textData: "Weight",
fontsize: 30.0,
fontweight: FontWeight.bold,
color: Color.fromARGB(255, 147, 148, 152)),
),
),
),
SizedBox(
height: 30,
),
Center(
child: Container(
height: size.height * 0.13,
width: size.width * 0.5,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(20),
border: Border.all(
color: Color.fromARGB(255, 92, 89, 89)),
),
child: ListWheelScrollView.useDelegate(
itemExtent: 100,
physics: FixedExtentScrollPhysics(),
onSelectedItemChanged: (i) {
print(numbers_Weight[i]);
},
childDelegate: ListWheelChildLoopingListDelegate(
children: <Widget>[
...numbers_Weight.map((String number) {
return Center(
child: Text(
number, //Here is the child value I would like to get
style: const TextStyle(
fontSize: 28.0,
color: Colors.white,
fontWeight: FontWeight.bold,
fontStyle: FontStyle.normal,
decoration: TextDecoration.none),
),
);
})
],
),
),
),
)
],
)
]),
),
],
),
);
}
}

Answer 1

Use show and hide to import part of a library.
// Import only foo.
import 'package:lib1/lib1.dart' show foo;
// Import all names EXCEPT foo.
import 'package:lib2/lib2.dart' hide foo;
See Using libraries for details.