实现这个主屏幕的最好方法是什么?

Question

我想为我的flutter应用程序创建一个主页。我使用了来自网络的模板，但不幸的是，我没有得到它的方式我在图片中勾画它。也许有人能帮我一下

sketch/result

不幸的是，我确信我不能做得更好:-/，我希望它完全像左边的(图标和颜色不是那么重要)

我使用了论坛上的这个链接作为appbar的模板，我很难插入它^^自定义AppBar Flutter

我也从论坛的某个地方得到了底部导航栏的代码，但我认为这无论如何都不适合我的目的。因为我不喜欢点击它时的收缩效果，所以边缘的两个箭头按钮应该在按下时弹回，而不是停留在按下状态，因为它们应该代表前面和后面的功能…

这里是完整的main.dart

import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
themeMode: ThemeMode.light,
theme: ThemeData(
primaryColor: Color(0xFF34445c),
primaryColorBrightness: Brightness.light,
brightness: Brightness.light,
primaryColorDark: Colors.black,
canvasColor: Color(0xFFCECECE),
appBarTheme: AppBarTheme(brightness: Brightness.light)),
darkTheme: ThemeData(
primaryColor: Colors.black,
primaryColorBrightness: Brightness.dark,
primaryColorLight: Colors.black,
brightness: Brightness.dark,
primaryColorDark: Colors.black,
indicatorColor: Colors.white,
canvasColor: Colors.black,
appBarTheme: AppBarTheme(brightness: Brightness.dark)),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final _selectedItemColor = Colors.white;
final _unselectedItemColor = Colors.white30;
final _selectedBgColor = Color(0xFF293749);
final _unselectedBgColor = Color(0xFF34445c);
int _selectedIndex = 0;
static const TextStyle optionStyle =
TextStyle(fontSize: 15, fontWeight: FontWeight.normal);
static const List<Widget> _widgetOptions = <Widget>[
Text(
'Index 0: ZURÜCK',
style: optionStyle,
),
Text(
'Index 1: FAVORITES',
style: optionStyle,
),
Text(
'Index 2: KOMMENTARE / LÖSCHEN',
style: optionStyle,
),
Text(
'Index 3: ABOUT-US',
style: optionStyle,
),
Text(
'Index 4: WEITER',
style: optionStyle,
),
];
void _onItemTapped(int index) {
setState(() {
_selectedIndex = index;
});
}
Color _getBgColor(int index) =>
_selectedIndex == index ? _selectedBgColor : _unselectedBgColor;
Color _getItemColor(int index) =>
_selectedIndex == index ? _selectedItemColor : _unselectedItemColor;
Widget _buildIcon(IconData iconData, String text, int index) => Container(
width: double.infinity,
height: kBottomNavigationBarHeight,
child: Material(
color: _getBgColor(index),
child: InkWell(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(iconData),
Text(text,
style: TextStyle(fontSize: 9, color: _getItemColor(index))),
],
),
onTap: () => _onItemTapped(index),
),
),
);
_appBar(height) => PreferredSize(
preferredSize:  Size(MediaQuery.of(context).size.width, height+80 ),
child: Stack(
children: <Widget>[
Container(
child: Center(
child: Text("TEXT", style: TextStyle(fontSize: 15.0,
fontWeight: FontWeight.w600,
color: Colors.white),
),
),
color:Theme.of(context).primaryColor,
height: height+75,
width: MediaQuery.of(context).size.width,
),
Container(
),
Positioned(    // To take AppBar Size only
top: 100.0,
left: 20.0,
right: 20.0,
child: AppBar(
backgroundColor: Color(0xFF293749),
leading: Icon(Icons.menu, color: Colors.white),
primary: false,
title: Container(
margin: EdgeInsets.only(top: 4.0, bottom: 4.0, right: 0.0, left: 0.0),
color: Colors.white,
child: Container(
margin: EdgeInsets.only(top: 0.0, bottom: 0.0, right: 5.0, left: 5.0),
child: TextField(
decoration: InputDecoration(
hintText: "Suchen",
border: InputBorder.none,
hintStyle: TextStyle(color: Colors.grey))),
),
),
actions: <Widget>[
IconButton(
icon: Icon(Icons.search, color: Colors.white), onPressed: () {},),
],
),
)
],
),
);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: _appBar(AppBar().preferredSize.height),
body: Center(
child: _widgetOptions.elementAt(_selectedIndex),
),
bottomNavigationBar: BottomNavigationBar(
selectedFontSize: 0,
items: <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: _buildIcon(Icons.arrow_back_ios_rounded, 'ZURÜCK', 0),
title: SizedBox.shrink(),
),
BottomNavigationBarItem(
icon: _buildIcon(Icons.favorite, 'FAVORITEN', 1),
title: SizedBox.shrink(),
),
BottomNavigationBarItem(
icon: _buildIcon(Icons.comment, 'KOMMENTARE', 2),
title: SizedBox.shrink(),
),
BottomNavigationBarItem(
icon: _buildIcon(Icons.info_outline_rounded, 'ÜBER UNS', 3),
title: SizedBox.shrink(),
),
BottomNavigationBarItem(
icon: _buildIcon(Icons.arrow_forward_ios_rounded, 'WEITER', 4),
title: SizedBox.shrink(),
),
],
currentIndex: _selectedIndex,
selectedItemColor: _selectedItemColor,
unselectedItemColor: _unselectedItemColor,
),
);
}
}

Answer 1

我已经用一些注释修改了你的代码，以支持你构建UI。

对于AppBar，您使用PreferredSize和Stack的方向是正确的，只需要进行一些小的调整。

对于BottomNavigationBar，由于提供的BottomNavigationBarItem已经具有icon和title属性，我们可以使用它并修改其父元素的颜色。这两个箭头按钮可以放在Row内。

完整示例如下:

import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
themeMode: ThemeMode.light,
theme: ThemeData(
primaryColor: Color(0xFF34445c),
primaryColorBrightness: Brightness.light,
brightness: Brightness.light,
primaryColorDark: Colors.black,
canvasColor: Color(0xFFCECECE),
appBarTheme: AppBarTheme(brightness: Brightness.light)),
darkTheme: ThemeData(
primaryColor: Colors.black,
primaryColorBrightness: Brightness.dark,
primaryColorLight: Colors.black,
brightness: Brightness.dark,
primaryColorDark: Colors.black,
indicatorColor: Colors.white,
canvasColor: Colors.black,
appBarTheme: AppBarTheme(brightness: Brightness.dark)),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final _selectedItemColor = Colors.white;
final _unselectedItemColor = Colors.white30;
final _selectedBgColor = Color(0xFF293749);
final _unselectedBgColor = Color(0xFF34445c);
int _selectedIndex = 0;
static const TextStyle optionStyle =
TextStyle(fontSize: 15, fontWeight: FontWeight.normal);
static const List<Widget> _widgetOptions = <Widget>[
Text(
'Index 0: ZURÜCK',
style: optionStyle,
),
Text(
'Index 1: FAVORITES',
style: optionStyle,
),
Text(
'Index 2: KOMMENTARE / LÖSCHEN',
style: optionStyle,
),
Text(
'Index 3: ABOUT-US',
style: optionStyle,
),
Text(
'Index 4: WEITER',
style: optionStyle,
),
];
_appBar() => PreferredSize(
preferredSize: Size.fromHeight(300),
child: Container(
height: 300,
child: Stack(
children: <Widget>[
Container(
color: Color(0xFF34445D),
height: 180,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
"APP TITLE",
style: TextStyle(
fontSize: 20.0,
fontWeight: FontWeight.w600,
color: Colors.white),
),
SizedBox(height: 20),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: List<Widget>.generate(
4,
(index) => Padding(
padding: EdgeInsets.symmetric(horizontal: 8.0),
child: Icon(Icons.people, color: Colors.white), // Sample icons for demonstration
),
),
)
],
),
),
Positioned(
top: 150.0,
left: 20.0,
right: 20.0,
child: Container(
color: Color(0xFF293749),
child: Row(
children: [
IconButton(
icon: Icon(Icons.menu, size: 40, color: Colors.white),
padding: EdgeInsets.zero,
onPressed: () {},
),
Expanded(
child: Container(
margin: EdgeInsets.symmetric(vertical: 3),
padding: EdgeInsets.only(left: 3),
color: Colors.white,
height: 30,
child: TextField(
style: TextStyle(color: Colors.black, fontSize: 12),
decoration: InputDecoration(
hintText: 'Search...',
border: InputBorder.none),
),
),
),
IconButton(
icon: Icon(Icons.search, size: 30, color: Colors.white),
padding: EdgeInsets.zero,
onPressed: () {},
),
],
),
),
),
],
),
),
);
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: _appBar(),
body: Center(
child: _widgetOptions.elementAt(_selectedIndex),
),
bottomNavigationBar: Container(
color: _selectedBgColor,
child: Row(
children: [
IconButton(
icon: Icon(Icons.arrow_back_ios, color: Colors.white),
onPressed: () {
setState(() {
_selectedIndex =
_selectedIndex <= 0 ? _selectedIndex : _selectedIndex - 1;
});
},
),
Expanded(
child: BottomNavigationBar(
type: BottomNavigationBarType.fixed, // Add the type here to avoid auto resize
backgroundColor: _selectedBgColor, // You can also set the unselectedBackgroundColor
currentIndex: _selectedIndex,
onTap: (index) => setState(() => _selectedIndex = index), // Update the selected index
selectedItemColor: _selectedItemColor,
unselectedItemColor: _unselectedItemColor,
items: <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(Icons.favorite), title: Text('FAVORITEN')),
BottomNavigationBarItem(
icon: Icon(Icons.comment), title: Text('KOMMENTARE')),
BottomNavigationBarItem(
icon: Icon(Icons.info_outline_rounded),
title: Text('ÜBER UNS')),
],
),
),
IconButton(
icon: Icon(Icons.arrow_forward_ios, color: Colors.white),
onPressed: () {
setState(() {
_selectedIndex =
_selectedIndex >= 2 ? _selectedIndex : _selectedIndex + 1;
});
},
),
],
),
),
);
}
}