在flutter中所有的组件都应该在放在MaterialApp—>Scaffold中 这是固定写法
import 'package:flutter/material.dart';
void main(List<String> args) {
runApp(MaterialApp(
debugShowCheckedModeBanner: false,//去掉模拟器左上角bug
home: Scaffold(
appBar: AppBar(//设置标题
title: const Text('你好flutter'),
),
body: const MyApp(),
),
));
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return const Center(
child: Text(
"你好 flutter11",
textDirection: TextDirection.rtl,
),
);
}
}
运行之后如下图所示
image.png
1.Container和 Text容器组件
import 'package:flutter/material.dart';
void main(){
runApp(
MaterialApp(
home: Scaffold(
appBar: AppBar(title: const Text("你好Flutter")),
body:Column(
children:const [
MyApp(),
MyButton(),
MyText()
]
)
),
)
);
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Center(
child:Container(
margin: const EdgeInsets.fromLTRB(0, 60, 0, 0),
alignment: Alignment.center, //配置Container容器内元素的方位
width: 200,
height: 200,
// transform:Matrix4.translationValues(0, -40, 0),// 位移
// transform:Matrix4.rotationZ(0.2),// 旋转
transform:Matrix4.skewY(.2),
decoration:BoxDecoration(
color: Colors.yellow, //背景颜色
border: Border.all( //边框
color: Colors.red,
width: 2
),
borderRadius:BorderRadius.circular(10), //配置圆角 也可以实现圆形
boxShadow: const[ //配置阴影效果
BoxShadow(
color:Colors.blue,
blurRadius:20.0
)
],
// LinearGradient 背景线性渐变 RadialGradient径向渐变
gradient:const LinearGradient(
colors:[
Colors.red,Colors.yellow
]
)
) ,
child: const Text("你好Flutter",style: TextStyle(
color: Colors.black,
fontSize: 20
),),
) ,
);
}
}
class MyButton extends StatelessWidget {
const MyButton({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Container(
alignment: Alignment.center,
width: 200,
height: 40,
// margin: const EdgeInsets.all(10), //四周margin
margin: const EdgeInsets.fromLTRB(0, 40, 0, 0),
// padding: const EdgeInsets.fromLTRB(40, 0, 0, 0),
decoration: BoxDecoration(
color: Colors.blue,
borderRadius:BorderRadius.circular(20)
),
child: const Text("按钮",style: TextStyle(
color: Colors.white,
fontSize: 20
)),
);
}
}
class MyText extends StatelessWidget {
const MyText({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Container(
width: 200,
height: 200,
margin: const EdgeInsets.fromLTRB(0, 40, 0, 0),
decoration: const BoxDecoration(
color: Colors.yellow
),
child: const Text(
"你好我是Flutter你好我是Flutter你好我是Flutter你好我是Flutter你好我是Flutter",
textAlign: TextAlign.left,
overflow: TextOverflow.ellipsis, //溢出显示几个点
maxLines: 1,
style: TextStyle(
fontSize: 20,
fontWeight:FontWeight.w900,
color: Colors.red,
fontStyle:FontStyle.italic,
letterSpacing:2,
decoration:TextDecoration.underline,
decorationColor: Colors.black,
decorationStyle: TextDecorationStyle.dashed
),
),
);
}
}
2.圆形图片
第一种
ClipOval(
child: Image.network("",
width: 150.0,
height: 150.0,
fit: BoxFit.cover),
),
第二种
CircleAvatar(
radius: 200,
backgroundImage:
NetworkImage(""),
),
3.ListView 用法 list是数组 itemCount的值是数组的长度 itemBuilder相当于 for循环赋值
Widget build(BuildContext context) {
return ListView.builder(
itemCount: list.length,
itemBuilder: (context, index) {
return ListTile(
title: Text("${list[index]}"),
);
});
}
4.GridView用法 list是数组 itemCount的值是数组的长度 itemBuilder相当于 for循环赋值
Widget build(BuildContext context) {
return GridView.builder(
//注意
gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisSpacing: 10.0, //水平子 Widget 之间间距
mainAxisSpacing: 10.0, //垂直子 Widget 之间间距
crossAxisCount: 2, //一行的 Widget 数量
),
itemCount: listData.length,
itemBuilder: _getListData,
);
}
5.Stack和Positioned定位用法
Widget build(BuildContext context) {
return Container(
decoration: const BoxDecoration(
borderRadius: BorderRadius.all(Radius.circular(8)),
color: Color.fromARGB(255, 255, 255, 255)),
// child: const Amap(),
child: Container(
width: double.infinity,//宽度占满
height: 240,
color: Colors.red,
child: Stack(//外面要包裹个Container 这样就是基于Container来定位
children: const [
Positioned(
left: 0,
top: 0,
child: Text('ceshi'),
),
Positioned(
right: 0,
bottom: 0,
child: Text(
'youxia',
style: TextStyle(fontSize: 24),
),
)
],
),
),
);
}
6.button按钮
image.png
@override
Widget build(BuildContext context) {
return ListView(
children: [
Column(
children: [
ElevatedButton(
style: ButtonStyle(
backgroundColor:
MaterialStateProperty.all(Colors.red), //修改按钮背景颜色
foregroundColor:
MaterialStateProperty.all(Colors.black), //修改按钮文字颜色
elevation: MaterialStateProperty.all(20), //添加阴影
shape: MaterialStateProperty.all(
RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10)), //圆角
)),
onPressed: () {
print('------');
},
child: const Text('普通按钮'),
),
ElevatedButton(
style: ButtonStyle(
//添加阴影
shape: MaterialStateProperty.all(
const CircleBorder(
side: BorderSide(color: Colors.yellow, width: 10),
), //圆角
)),
onPressed: () {
print('------');
},
child: const Text('圆形按钮'),
),
TextButton(
onPressed: () {
print("-----");
},
child: const Text('文本按钮'),
),
OutlinedButton(
onPressed: () {
print('带边框的按钮');
},
child: const Text('带边框按钮'),
),
IconButton(
onPressed: () {
print('----');
},
icon: const Icon(Icons.tab),
),
ElevatedButton.icon(
onPressed: () {
print('---');
},
icon: const Icon(Icons.safety_check),
label: const Text('带图标按钮'),
),
TextButton.icon(
onPressed: () {
print('---');
},
icon: const Icon(Icons.safety_check),
label: const Text('带图标按钮'),
),
OutlinedButton.icon(
onPressed: () {
print('---');
},
icon: const Icon(Icons.safety_check),
label: const Text('带图标按钮'),
),
Container(
width: 240,
height: 60,
child: ElevatedButton(
onPressed: () {
print('----');
},
child: const Text("自定义按钮大小")),
),
Row(
children: [
Expanded(
flex: 1,
child: SizedBox(
child: ElevatedButton(
onPressed: () {
print('----');
},
child: const Text("占满宽度的按钮"),
),
),
)
],
)
],
),
],
);
}
7.Warp组件
Wrap(
spacing: 10,
runSpacing: 10,
children: [
Button("女装", onPressed: () {}),
Button("笔记本", onPressed: () {}),
Button("玩具", onPressed: () {}),
Button("文学", onPressed: () {}),
Button("女装", onPressed: () {}),
Button("时尚", onPressed: () {}),
Button("男装", onPressed: () {}),
Button("xxxx", onPressed: () {}),
Button("手机", onPressed: () {})
],
),
8.咸鱼中间突起按钮
image.png
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text("Flutter App")),
body: _pages[_currentIndex],
bottomNavigationBar: BottomNavigationBar(
fixedColor: Colors.red, //选中的颜色
// iconSize:35, //底部菜单大小
currentIndex: _currentIndex, //第几个菜单选中
type: BottomNavigationBarType.fixed, //如果底部有4个或者4个以上的菜单的时候就需要配置这个参数
onTap: (index) {
//点击菜单触发的方法
//注意
setState(() {
_currentIndex = index;
});
},
items: const [
BottomNavigationBarItem(icon: Icon(Icons.home), label: "首页"),
BottomNavigationBarItem(icon: Icon(Icons.category), label: "分类"),
BottomNavigationBarItem(icon: Icon(Icons.message), label: "消息"),
BottomNavigationBarItem(icon: Icon(Icons.settings), label: "设置"),
BottomNavigationBarItem(icon: Icon(Icons.people), label: "用户")
]),
floatingActionButton: Container(
height: 60, //调整FloatingActionButton的大小
width: 60,
padding: const EdgeInsets.all(5),
margin: const EdgeInsets.only(top: 5), //调整FloatingActionButton的位置
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(30),
),
child: FloatingActionButton(
backgroundColor:_currentIndex==2?Colors.red:Colors.blue,
child: const Icon(Icons.add),
onPressed: () {
setState(() {
_currentIndex=2;
});
}
),
),
floatingActionButtonLocation:
FloatingActionButtonLocation.centerDocked, //配置浮动按钮的位置
);
}
9.左右侧边栏
image.png
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
debugShowCheckedModeBanner: false,
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: Scaffold(
appBar: AppBar(
title: const Text('高德地图'),
),
body: const MyHomePage(),
drawer: Drawer(
//左侧侧边栏
child: Column(
children: [
Row(
children: [
Expanded(
flex: 1,
child: DrawerHeader(
decoration: const BoxDecoration(
// color: Colors.yellow,
image: DecorationImage(
image: NetworkImage( ""),
fit: BoxFit.cover)),
child: Column(
children: const [
ListTile(
leading: CircleAvatar(
backgroundImage: NetworkImage("")),
title: Text("张三",
style: TextStyle(color: Colors.red)),
),
ListTile(
title: Text("邮箱：xxxx@qq.com"),
)
],
),
))
],
),
const ListTile(
leading: CircleAvatar(
child: Icon(Icons.people),
),
title: Text("个人中心"),
),
const Divider(),
const ListTile(
leading: CircleAvatar(
child: Icon(Icons.settings),
),
title: Text("系统设置"),
),
Divider(),
],
),
),
endDrawer: const Drawer(
//右侧侧边栏
child: Text("右侧侧边栏"),
),
),
);
}
10.导航栏左右侧图标
image.png
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
debugShowCheckedModeBanner: false,
theme: ThemeData(
// This is the theme of your application.
//p
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
appBarTheme: const AppBarTheme(centerTitle: true)),//标题居中
home: Scaffold(
appBar: AppBar(
title: const Text('测试'),
leading: IconButton(
//左侧图标
onPressed: () {
print("2112");
},
icon: const Icon(Icons.access_alarm),
),
backgroundColor: Color.fromARGB(255, 43, 0, 234),
actions: [
//右侧图标
IconButton(
onPressed: () {
Navigator.of(context).pushReplacementNamed("/pagename");
Navigator.of(context).pushAndRemoveUntil(
MaterialPageRoute(builder: (BuildContext context) {
return const Amap();
}), (route) => false);
Navigator.of(context).pop();
Navigator.of(context).push(
MaterialPageRoute(
builder: (BuildContext context) {
return const Amap();
},
),
);
},
icon: const Icon(Icons.access_alarm_outlined),
),
IconButton(
onPressed: () {
print("----");
},
icon: const Icon(Icons.account_balance_outlined),
),
],
),
body: const MyHomePage(),
// drawer: Drawer(
// //左侧侧边栏
// child: Column(
// children: [
// Row(
// children: [
// Expanded(
// flex: 1,
// child: DrawerHeader(
// decoration: const BoxDecoration(
// // color: Colors.yellow,
// image: DecorationImage(
// image: NetworkImage(
// "https://www.itying.com/images/flutter/2.png"),
// fit: BoxFit.cover)),
// child: Column(
// children: const [
// ListTile(
// leading: CircleAvatar(
// backgroundImage: NetworkImage(
// "https://www.itying.com/images/flutter/3.png")),
// title: Text("张三",
// style: TextStyle(color: Colors.red)),
// ),
// ListTile(
// title: Text("邮箱：xxxx@qq.com"),
// )
// ],
// ),
// ))
// ],
// ),
// const ListTile(
// leading: CircleAvatar(
// child: Icon(Icons.people),
// ),
// title: Text("个人中心"),
// ),
// const Divider(),
// const ListTile(
// leading: CircleAvatar(
// child: Icon(Icons.settings),
// ),
// title: Text("系统设置"),
// ),
// Divider(),
// ],
// ),
// ),
// endDrawer: const Drawer(
// //右侧侧边栏
// child: Text("右侧侧边栏"),
// ),
),
);
}
11.跳转路由
第一种
Navigator.of(context).push(
MaterialPageRoute(
builder: (BuildContext context) {
return const Amap();
},
),
);
返回上级路由
Navigator.of(context).pop();
替换路由跳转
Navigator.of(context).pushReplacementNamed("/pagename");
返回根目录
Navigator.of(context).pushAndRemoveUntil(
MaterialPageRoute(builder: (BuildContext context) {
return const Amap();
}), (route) => false);
12.页面传值
微信图片_20221229101000.png
13.Dialog 弹窗 也可以使用插件 flutter Toast
https://pub.dev/packages/fluttertoast/install
image.png
@override
Widget build(BuildContext context) {
return Center(
child: Container(
child: ElevatedButton(
onPressed: () {
print("[[[[[[[[");
showDialog(
context: context,
builder: (context) {
return AlertDialog(
title: Text("标题"),
content: Text("内容"),
actions: [
TextButton(
onPressed: () {
print("-------");
Navigator.of(context).pop();
},
child: const Text('确定'),
),
TextButton(
onPressed: () {
Navigator.of(context).pop();
print("-------");
},
child: const Text("取消"),
),
],
);
});
},
child: const Text('测试按钮'),
),
),
);
}
image.png
@override
Widget build(BuildContext context) {
return Center(
child: Container(
child: ElevatedButton(
onPressed: () {
print("[[[[[[[[");
showDialog(
barrierDismissible: false, //点击灰色背景是否让弹窗消失
context: context,
builder: (context) {
return SimpleDialog(
title: Text('请选择语言'),
children: [
SimpleDialogOption(
onPressed: () {
print("汉语");
Navigator.of(context).pop();
},
child: const Text('汉语'),
),
const Divider(),
SimpleDialogOption(
onPressed: () {
print("汉语");
},
child: const Text('汉语'),
),
const Divider(),
SimpleDialogOption(
onPressed: () {
print("汉语");
},
child: const Text('汉语'),
),
],
);
});
},
child: const Text('测试按钮'),
),
),
);
}
14.PageView
@override
Widget build(BuildContext context) {
return PageView.builder(
scrollDirection: Axis.vertical,
itemBuilder: (context, index) {
return Center(
child: Text("第$index屏"),
);
},
itemCount: 10,
onPageChanged: (index) {
print(index);
},
);
}
15.AnimatedList
class _HomePageState extends State<HomePage> {
final _globalKey = GlobalKey<AnimatedListState>();
bool flag = true;
List<String> list = ["第一条", "第二条"];
Widget _buildItem(index) {
return ListTile(
key: ValueKey(index),
title: Text(list[index]),
trailing: IconButton(
icon: const Icon(Icons.delete),
onPressed: () {
//执行删除
_deleteItem(index);
},
),
);
}
_deleteItem(index) {
if (flag == true) {
flag = false;
//执行删除
_globalKey.currentState!.removeItem(index, (context, animation) {
//animation的值是从1到0
var removeItem = _buildItem(index);
list.removeAt(index); //数组中删除数据
return ScaleTransition(
// opacity: animation,
scale: animation,
child: removeItem, //删除的时候执行动画的元素
);
});
//解决快速删除的bug
Timer.periodic(const Duration(milliseconds: 500), (timer) {
flag = true;
timer.cancel();
});
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Title'),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {
list.add("我是新增的数据");
_globalKey.currentState!.insertItem(list.length - 1);
},
),
body: AnimatedList(
key: _globalKey,
initialItemCount: list.length,
itemBuilder: ((context, index, animation) {
//animation的值是从0到1
return FadeTransition(
opacity: animation,
child: _buildItem(index),
);
})),
);
}
}
16.表单
Screenshot_20230101_115045.png
Screenshot_20230101_115122.png
ListView(
padding: const EdgeInsets.all(10),
children: [
const TextField(),
const SizedBox(height: 20),
const TextField(
decoration: InputDecoration(border: OutlineInputBorder())),
const SizedBox(height: 20),
const TextField(
decoration: InputDecoration(
hintText: "请输入用户名", border: OutlineInputBorder())),
const SizedBox(height: 20),
const TextField(
obscureText: true, //配置密码框
decoration: InputDecoration(
hintText: "请输入密码", border: OutlineInputBorder())),
const SizedBox(height: 20),
TextField(
decoration: InputDecoration(
hintText: "请输入密码",
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(20),
))),
const SizedBox(height: 20),
const TextField(
decoration: InputDecoration(
icon: Icon(Icons.add),
hintText: "请输入网址",
prefixText: "http://",
prefixIcon: Icon(Icons.lock),
border: OutlineInputBorder())),
const SizedBox(height: 20),
const TextField(
decoration: InputDecoration(
prefixIcon: Icon(Icons.people),
hintText: "请输入用户名",
border: OutlineInputBorder()),
),
const SizedBox(height: 10),
const TextField(
obscureText: true,
decoration: InputDecoration(
prefixIcon: Icon(Icons.lock),
hintText: "请输入密码",
border: OutlineInputBorder()),
),
const SizedBox(height: 20),
const TextField(
decoration: InputDecoration(
suffixIcon: Icon(Icons.close),
hintText: "请输入关键词",
border: OutlineInputBorder()),
),
SizedBox(height: 20),
const TextField(
maxLines: 4,
decoration: InputDecoration(
border: OutlineInputBorder()
),
)
],
)
```
网友评论