【发布时间】：2021-03-16 13:26:46
【问题描述】：
我正在为我的大学项目做项目，但我遇到了问题。
首先，我想在我的入职屏幕上添加一个背面，但我已经在右下角使用 align 来表示“下一个”，而我希望在左下角使用背面
第二，我想把标题（欢迎，目的，创作者）放在中间，但我不能把它放在中间，因为我使用的是 sizebox
第三，我希望引导屏幕只出现一次，所以当打开它的用户不会再看到它（基本上是第一次打开，引导屏幕，但第二次直接进入主页）
对不起我的英语 如果您想可视化，请拍照： Photo 代码如下：
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import '../home_screen.dart';
class Onboarding extends StatefulWidget {
@override
_OnboardingScreen createState() => _OnboardingScreen();
}
class _OnboardingScreen extends State<Onboarding> {
final int _numPages = 3;
final PageController _pageController = PageController(initialPage: 0);
int _currentPage = 0;
List<Widget> _buildPageIndicator() {
List<Widget> list = [];
for (int i = 0; i < _numPages; i++) {
list.add(i == _currentPage ? _indicator(true) : _indicator(false));
}
return list;
}
Widget _indicator(bool isActive) {
return AnimatedContainer(
duration: Duration(milliseconds: 150),
margin: EdgeInsets.symmetric(horizontal: 8.0),
height: 8.0,
width: isActive ? 24.0 : 16.0,
decoration: BoxDecoration(
color: isActive ? Colors.white : Color(0xFF7B51D3),
borderRadius: BorderRadius.all(Radius.circular(12)),
),
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: AnnotatedRegion<SystemUiOverlayStyle>(
value: SystemUiOverlayStyle.light,
child: Container(
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topCenter,
end: Alignment.bottomCenter,
stops: [0.1, 0.4, 0.7, 0.9],
colors: [
Colors.black,
Color(0xff112339),
Color(0xff112339),
Colors.black,
],
),
),
child: Padding(
padding: EdgeInsets.symmetric(vertical: 40.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Container(
alignment: Alignment.centerRight,
child: FlatButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => HomePage()),
);
},
child: Text(
'Skip',
style: TextStyle(
color: Colors.white,
fontSize: 20.0,
),
),
),
),
Container(
height: 600.0,
child: PageView(
physics: ClampingScrollPhysics(),
controller: _pageController,
onPageChanged: (int page) {
setState(() {
_currentPage = page;
});
},
children: <Widget>[
Padding(
padding: EdgeInsets.only(top:70.0,left: 40.0,right: 40.0,),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Center(
child: Image(
image: AssetImage(
'assets/images/Logo.png',
),
height: 120.0,
width: 120.0,
),
),
SizedBox(height: 50.0),
Text(
'Welcome',
style: TextStyle(
color: Colors.white,
fontSize: 21.0,
height: 1.5,
),
),
SizedBox(height: 30.0),
Text(
'Welcome to Moviez, the place where you will spend your time magically',
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
height: 1.2,
fontFamily: 'Raleway',
),
),
],
),
),
Padding(
padding: EdgeInsets.only(top:70.0,left: 40.0,right: 40.0,),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Center(
child: Image(
image: AssetImage(
'assets/images/Logo.png',
),
height: 120.0,
width: 120.0,
),
),
SizedBox(height: 50.0),
Text(
'Purpose',
style: TextStyle(
color: Colors.white,
fontSize: 21.0,
height: 1.5,
),
),
SizedBox(height: 30.0),
Text(
'This App is for educational purposes only',
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
height: 1.2,
),
),
],
),
),
Padding(
padding: EdgeInsets.only(top:70.0,left: 40.0,right: 40.0,),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Center(
child: Image(
image: AssetImage(
'assets/images/Logo.png',
),
height: 120.0,
width: 120.0,
),
),
SizedBox(height: 50.0),
Text(
'Creator',
style: TextStyle(
color: Colors.white,
fontSize: 21.0,
height: 1.5
),
),
SizedBox(height: 30.0),
Text(
'Adela, Caroline, Cordellya, David, Valentino',
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
height: 1.2,
),
),
],
),
),
],
),
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: _buildPageIndicator(),
),
_currentPage != _numPages - 1
? Expanded(
child: Align(
alignment: FractionalOffset.bottomRight,
child: FlatButton(
onPressed: () {
_pageController.nextPage(
duration: Duration(milliseconds: 500),
curve: Curves.ease,
);
},
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Text(
'Next',
style: TextStyle(
color: Colors.white,
fontSize: 22.0,
),
),
SizedBox(width: 10.0),
Icon(
Icons.arrow_forward,
color: Colors.white,
size: 30.0,
),
],
),
),
),
)
: Text(''),
],
),
),
),
),
bottomSheet: _currentPage == _numPages - 1
? Container(
height: 100.0,
width: double.infinity,
color: Colors.white,
child: GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => HomePage()),
);
},
child: Center(
child: Padding(
padding: EdgeInsets.only(bottom: 30.0),
child: Text(
'Get started',
style: TextStyle(
color: Color(0xFF5B16D0),
fontSize: 20.0,
fontWeight: FontWeight.bold,
),
),
),
),
),
)
: Text(''),
);
}
}
这是我的 main.dart
import 'package:flutter/material.dart';
import 'package:movie_app/screens/home_screen/widgets/onboard.dart';
import 'screens/home_screen/home_screen.dart';
void main() {
runApp(MyApp());
Paint.enableDithering = true;
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Movie App',
theme: ThemeData(
primarySwatch: Colors.blue,
iconTheme: IconThemeData(
color: Colors.white,
),
textTheme: ThemeData.light().textTheme.copyWith(
bodyText1: TextStyle(
// fontFamily: 'OpenSans',
// fontWeight: FontWeight.bold,
fontSize: 22,
color: Colors.white,
),
button: TextStyle(
color: Colors.white,
),
),
appBarTheme: AppBarTheme(
iconTheme: IconThemeData(color: Colors.white),
actionsIconTheme: IconThemeData(size: 30),
)),
home: Onboarding(),
);
}
}
【问题讨论】：