Configuration:
Question 1:
Running Gradle task ‘assembleDebug’… Not moving for a long time
Flutter installation directory, / packages/flutter_tools/gradle/flutter in the gradle:
- Private static final String up your MAVEN_REPO = “storage.googleapis.com/download.fl…” ;
- Changed to a private static final String up your MAVEN_REPO = “mirrors.tuna.tsinghua.edu.cn/flutter/dow…” ;
1. Align the component
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'the ALign components',
home: Scaffold(
appBar: AppBar(
title: Text('the Align components')
),
body: Container(
width: 200.0,
height: 300.0./ * ** ALign's widthFactor is invalid when the width of the container is specified
*
* /
/ / = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
color: Colors.red,
child: Align(
// Alignment
alignment: Alignment(0.1.0),
/ * ** Alignment. Center = bottomCenter. TopRight
* Alignment: The range of alignment (0,0) ranges from -1.0 to 1.0
* * /
/ / = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
widthFactor: 3.0.// Double the width (padding the parent container size according to the child component size)
heightFactor: 4.0.// Double the width (depending on the size of the child component)
/ * ** When the parent container is of uncertain width and height
* If no Container is specified
* * /
/ / = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
child: Container(
color: Colors.green,
width: 100.0,
height: 50.0,
child: Text(
'bottomCentent', style: TextStyle( color: Colors.white ) ) ), ) ) ), ); }}Copy the code2.AppBar
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'the ALign components',
home: Scaffold(
appBar: AppBar(
title: Text('the Align components') ), body: DemoPage() ), ); }}class DemoPage extends StatefulWidget {
@override
_DemoPageState createState() => _DemoPageState();
}
class _DemoPageState extends State<DemoPage>{
@override
Widget build(BuildContext context) {
return SizedBox(
height: 200.0,
child: AppBar(
title: Text('application'),
actions: <Widget>[
IconButton(
icon: Icon(Icons.print),
onPressed: null,
tooltip: 'print',
),
IconButton(
icon: Icon(Icons.plus_one),
onPressed: null,
tooltip: 'more',
),
IconButton(
icon: Icon(Icons.share),
onPressed: null,
tooltip: 'sharing'[, [, [, [; }}Copy the code
import 'package:flutter/material.dart';
void main(){
runApp(
MyApp()
);
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'the ALign components',
home: Scaffold(
appBar: AppBar(
title: Text('title'),
// Left icon
leading: Icon(Icons.home),
// Background of the entire AppBar
backgroundColor: Colors.green,
// Center the title
centerTitle: true.// Icon on the right
actions: <Widget>[
IconButton(
icon: Icon(Icons.share),
onPressed: null,
tooltip: 'sharing',),// Menu button
PopupMenuButton<String>(
itemBuilder: (BuildContext content) => <PopupMenuItem<String> > [/ / the menu item
PopupMenuItem<String>(
value: 'friend',
child: Text('Share in moments'),
),
PopupMenuItem<String>(
value: 'download',
child: Text('Download to local'), ) ], ) ], ), body: DemoPage() ), ); }}class DemoPage extends StatefulWidget {
@override
_DemoPageState createState() => _DemoPageState();
}
class _DemoPageState extends State<DemoPage>{
@override
Widget build(BuildContext context) {
return SizedBox(
height: 500,
child: AppBar(
title: Text('title'),
// Left icon
leading: Icon(Icons.home),
// Background of the entire AppBar
backgroundColor: Colors.green,
// Center the title
centerTitle: true.// Icon on the right
actions: <Widget>[
IconButton(
icon: Icon(Icons.share),
onPressed: null,
tooltip: 'sharing',),// Menu button
PopupMenuButton<String>(
itemBuilder: (BuildContext content) => <PopupMenuItem<String> > [/ / the menu item
PopupMenuItem<String>(
value: 'friend',
child: Text('Share in moments'),
),
PopupMenuItem<String>(
value: 'download',
child: Text('Download to local'() [() [() [() [() }}Copy the code
3. BottomAppBar components
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'BottomAppBar components',
home: Scaffold(
// FAB button position
floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked, // Hover in the middle of the bottom
/ / FAB button
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: null,),// Bottom app bar
bottomNavigationBar: BottomAppBar(
// The distance between floatingActionButton and BottomAppBar
notchMargin: 10.0.// Apply the background color at the bottom
color: Colors.pink,
child: Row(
// Set the size
mainAxisSize: MainAxisSize.max,
// Alignment
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
IconButton(
icon: Icon(Icons.menu),
onPressed: (){},
),
IconButton(
icon: Icon(Icons.search),
onPressed: (){},
)
]
),
),
body: null)); }}Copy the code
4. The ButtonBar components
@override
Widget build(BuildContext context) {
// End button aligned container
return Center(
child: ButtonBar(
// Alignment defaults to end alignment
alignment: MainAxisAlignment.end,
/ / the child size
mainAxisSize: MainAxisSize.min,
children: <Widget>[
RaisedButton(
child: Text('home'),
color: Colors.yellowAccent,
onPressed: null
),
RaisedButton(
child: Text('release'),
color: Colors.yellow,
onPressed: null
),
RaisedButton(
child: Text('I'),
color: Colors.yellowAccent,
onPressed: null))); }Copy the code5. FlexibleSpace components
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'FlexibleSpace components',
home: Scaffold(
appBar: AppBar(
title: Text('FlexibleSpace components')
),
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled){
return <Widget>[
SliverAppBar(
// Expand the height
expandedHeight: 150.0.// Whether to hide with sliding
floating: false.// Whether it is fixed at the top
pinned: true,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'Foldable component',
style: TextStyle(
color: Colors.white
),
),
background: Image.network('https://ss0.bdstatic.com/94oJfD_bAAcT8t7mm9GUKT-xh_/timg?image&quality=100&size=b4000_4000&sec=1590326522&di=83b46be42e 8b62d86b43ecc4d9731e17&src=http://www.bizhidaquan.com/d/file/1/1159829.jpg')))]; }, body: Center( child: Text('Pull up')))),); }}Copy the code
6. SliverAppBar components
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'SliverAppBar components',
home: Scaffold(
appBar: AppBar(
title: Text('SliverAppBar components') ), body: Domes() ), ); }}// Scrollable component
class Domes extends StatelessWidget {
@override
Widget build(BuildContext context) {
return NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxScrolled){
return <Widget>[
SliverAppBar(
// Whether to reserve the height
primary: true.// Left icon
leading: Icon(Icons.hdr_off),
// Icon on the right
actions: <Widget>[
Icon(Icons.add)
],
// Z-shadow
elevation: 10.0.// True fixed at the top false completely hidden
pinned: false.// Expandable area height
expandedHeight: 200.0.// Used together with floating
snap: false.// Whether to hide the title with sliding
floating: false.// Extend the area
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'This is a title.',
style: TextStyle(
color: Colors.yellow,
fontSize: 16.0
)
),
background: Image.network(
'https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1590337388247&di=6637f1e38c9da6fa343735f749080e24&i mgtype=0&src=http%3A%2F%2Fimg4.imgtn.bdimg.com%2Fit%2Fu%3D3004831859%2C2611273449%26fm%3D214%26gp%3D0.jpg'),),)]; }, body: Center( child: Text('drag'))); }}Copy the code
7. SnackBar components
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'SnackBar components',
home: Scaffold(
appBar: AppBar(
title: Text('SnackBar components') ), body: Domes() ), ); }}// Scrollable component
class Domes extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: GestureDetector(
onTap:(){
final snackBar = SnackBar(
// Prompt message
content: Text('Text prompt'),
/ / the background color
backgroundColor: Colors.green,
/ / operation
action: SnackBarAction(
textColor: Colors.white,
label: 'cancel',
onPressed: (){
}
),
// The duration
duration: Duration(minutes: 1), / / 1 minutes
);
Scaffold.of(context).showSnackBar(snackBar);// final snackBar
},
child: Text('Show message at bottom of screen'))); }}Copy the code
8. TabBar component
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'TabBar component',
home: Scaffold(
appBar: AppBar(
title: Text('TabBar component') ), body: DemoPage() ), ); }}/ / SingleTickerProviderStateMixin switch (animation) must be used in a stateful components
class DemoPage extends StatefulWidget {
@override
_DemoPageState createState() => _DemoPageState();
}
class _DemoPageState extends State<DemoPage> with SingleTickerProviderStateMixin {
ScrollController _scrollViewController;
TabController _tabController;
// Initialization is complete
@override
void initState(){
super.initState();
_scrollViewController = ScrollController();
// The length should be the same as the display section
_tabController = TabController(vsync: this, length: 6);
}
// Apply destruction
@override
void dispose(){
super.initState();
/ / destroy
_scrollViewController.dispose();
_tabController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
// End button aligned container
return SizedBox(
height: 500.0,
child: Scaffold(
appBar: AppBar(
title: Text('选项卡'),
// The front icon
leading: Icon(Icons.home),
/ / the background color
backgroundColor: Colors.blue,
// Title TAB
bottom: TabBar(
controller: _tabController,
// Whether to scroll
isScrollable: true,
tabs: <Widget>[
Tab(
text: "Option 1",
icon: Icon(Icons.home),
),
Tab(
text: "Option 2"
),
Tab(text: "Option 3"),
Tab(text: "Option 4"),
Tab(text: "Option 5"),
Tab(text: "Option 6"),),),// Switch the content
body: TabBarView(controller: _tabController,
children: <Widget>[
Text('option 1'),
Text('option 2'),
Text('option 3'),
Text('option 4'),
Text('option 5'),
Text('option 6'() [(), (); }}Copy the code
9. BottomNavigationBar components
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'BottomNavigationBar components',
home: Scaffold(
appBar: AppBar(
title: Text('BottomNavigationBar components')
),
body: Container(
width: 200.0,
height: 500.0), bottomNavigationBar: DemoPage(), ), ); }}class DemoPage extends StatefulWidget {
@override
_DemoPageState createState() => _DemoPageState();
}
class _DemoPageState extends State<DemoPage> {
/ / the current Index
int _currentIndex = 1;
void _onItemTapped(int index){
print(index);
setState(() {
_currentIndex = index;
});
}
@override
Widget build(BuildContext context) {
return BottomNavigationBar(
// Bottom button type
type: BottomNavigationBarType.fixed, / / fixed fixed
// Button size
iconSize: 24.0,
onTap: _onItemTapped,
// Current index
currentIndex: _currentIndex,
// Select the color
fixedColor: Colors.red,
items: <BottomNavigationBarItem>[
BottomNavigationBarItem(
title: Text('chat'),
icon: Icon(Icons.home)
),
BottomNavigationBarItem(
title: Text('Address book'),
icon: Icon(Icons.home)
),
BottomNavigationBarItem(
title: Text('I'), icon: Icon(Icons.home) ) ] ); }}Copy the code
10. BottomNavigationBar components
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'BottomNavigationBar components',
home: Scaffold(
appBar: AppBar(
title: Text('BottomNavigationBar components')
),
body: Center(
child: Column(
children: <Widget>[
// Add a box of the specified size, with the maximum width and minimum height
ConstrainedBox(
constraints: const BoxConstraints(
maxHeight: 100.0,
minHeight: 20.0,
maxWidth: 200.0,
minWidth: 60.0
),
child: Container(
width: 150.0,
height: 100,
color: Colors.blue,
child: Text(
'Width>maxWidth', style: TextStyle( color: Colors.yellow ) ) ), ) ] ) ), bottomNavigationBar: DemoPage(), ), ); }}Copy the code