原项目可以在https://github.com/abuanwar072/Welcome-Login-Signup-Page-Flutter找到,官方录制了相应的视频在https://www.youtube.com/watch?v=ExKYjqgswJg&feature=youtu.be上,基于此编写学习的过程,本项目地址https://github.com/tianrandailove/flutter_auth。
实现欢迎页
- 首先定义主题的颜色,我们在lib目录下创建constant目录,并创建color_constant.dart 文件。
import 'package:flutter/material.dart';
const kPrimaryColor = Color(0xFF6F35A5); //深色
const kPrimaryLightColor = Color(0xFFF1E6FF); //浅色
- 准备资源文件,在根目录下创建assets文件,并将资源拷贝到这里,并编辑pubspec.yaml文件配置资源文件的引用。
flutter:
# The following line ensures that the Material Icons font is
# included with your application, so that you can use the icons in
# the material Icons class.
uses-material-design: true
# To add assets to your application, add an assets section, like this:
assets:
- assets/images/
- assets/icons/
- 需要使用flutter_svg渲染svg资源,编辑pubspec.yaml文件,引入flutter_svg包。
dependencies:
flutter:
sdk: flutter
# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^0.1.3
flutter_svg: ^0.17.4
dev_dependencies:
flutter_test:
sdk: flutter
# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec
- 执行 pub get 命令。
- 在lib目录下创建pages/welcome目录。
- 先看下welcome页面的构成,整个页面由背景层和前景层组成,因此整个界面使用stack布局,使用Positioned配合布局背景层,column布局前景层。在pages/welcome目录下创建components目录(存放背景层和前景层)。
- 在components目录下创建background.dart 文件,该文件用于渲染welcome页面背景。
import 'package:flutter/material.dart';
class Background extends StatelessWidget{
final Widget child;
const Background({Key key,@required this.child}):super(key:key);
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
height: size.height,
width: double.infinity,
child: Stack(
alignment: Alignment.center,
children: [
Positioned(
top: 0,
left: 0,
child: Image.asset("assets/images/main_top.png",
width: size.width*0.3,),
),
Positioned(
bottom: 0,
left: 0,
child: Image.asset("assets/images/main_bottom.png",
width: size.width*0.2,),
)
,
child,
],
),
);
}
}
- 修改main.dart文件,删除其他代码,只保留 main函数和MyApp类的代码,并替换home节点的内容
import 'package:flutter/material.dart';
import 'package:flutterauth/pages/welcome/components/background.dart';
import 'package:flutterauth/pages/welcome/welcome.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Auth',
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,
// This makes the visual density adapt to the platform that you run
// the app on. For desktop platforms, the controls will be smaller and
// closer together (more dense) than on mobile platforms.
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: Scaffold(
body: Background(
child: Center(
child: Text('WELCOME'),
),
),
),
);
}
}
- 运行App,如下:
- 在lib目录下创建widgets目录,在widgets目录下创建rounded_button.dart文件,这里实现一个圆角按钮,内容如下。
import 'package:flutter/material.dart';
import 'package:flutterauth/constant/color_constant.dart';
class RoundedButton extends StatelessWidget {
final String text;
final Function press;
final Color color, textColor;
const RoundedButton(
{Key key,
this.text,
this.press,
this.color = kPrimaryColor,
this.textColor = Colors.white})
: super(key: key);
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
margin: EdgeInsets.symmetric(
vertical: 10,
),
width: size.width * 0.8,
child: ClipRRect(
borderRadius: BorderRadius.circular(29),
child: FlatButton(
padding: EdgeInsets.symmetric(vertical: 20, horizontal: 40),
color: color,
onPressed: press,
child: Text(
text,
style: TextStyle(color: textColor),
),
),
),
);
}
}
- 接下来在components目录下创建body.dart 文件,该文件用于渲染前景层。
import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:flutterauth/constant/color_constant.dart';
import 'package:flutterauth/pages/login/login.dart';
import 'package:flutterauth/pages/signup/sign_up.dart';
import 'package:flutterauth/pages/welcome/components/background.dart';
import 'package:flutterauth/pages/widgets/rounded_button.dart';
class Body extends StatelessWidget{
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Background(
child: SingleChildScrollView(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text("WELCOME",
style: TextStyle(fontWeight:FontWeight.bold),),
SizedBox(height: size.height*0.05,),
SvgPicture.asset("assets/icons/chat.svg",height: size.height*0.45,),
SizedBox(height: size.height*0.05,),
RoundedButton(
text: "SIGN IN",
press: (){
},
),
RoundedButton(
text:"SIGN UP",
color: kPrimaryLightColor,
textColor: Colors.black,
press:(){
},
)
],
),
)
);
}
}
- 修改main.dart文件,将Background节点的child设置成刚刚创建Body实例。
home: Scaffold(
body: Background(
child:Body(),
),
),
- 运行App。
- 在welcome目录下创建welcome.dart文件,将整个welcome页面的渲染内容放到这个文件中。
import 'package:flutter/material.dart';
import 'package:flutterauth/pages/welcome/components/body.dart';
class Welcome extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Body(),
);
}
}
- 修改main.dart文件的home节点为Welcome实例。
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Auth',
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,
// This makes the visual density adapt to the platform that you run
// the app on. For desktop platforms, the controls will be smaller and
// closer together (more dense) than on mobile platforms.
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: Welcome(),
);
}
实现登录页
- 在pages目录下创建login目录,在login下创建components目录。
- 登录页面和欢迎页面一样,采用背景层和前景层的布局方式。
- 在components目录下创建background.dart文件实现背景层。
import 'package:flutter/material.dart';
class Background extends StatelessWidget {
final Widget child; //前景层元素做为子元素
const Background({Key key, @required this.child}) : super(key: key);
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
width: double.infinity,
height: size.height,
child: Stack(
alignment: Alignment.center,
children: [
Positioned(
top: 0,
left: 0,
child: Image.asset(
"assets/images/main_top.png",
width: size.width * 0.35,
),
),
Positioned(
bottom: 0,
right: 0,
child: Image.asset(
"assets/images/login_bottom.png",
width: size.width * 0.4,
),
),
child,
],
),
);
}
}
- 在lib/widgets创建text_field_container.dart文件,实现一个文本框容器。
import 'package:flutter/material.dart';
import 'package:flutterauth/constant/color_constant.dart';
class TextFieldContainer extends StatelessWidget {
final Widget child;
const TextFieldContainer({Key key, @required this.child}) : super(key: key);
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
margin: EdgeInsets.symmetric(vertical: 10),
padding: EdgeInsets.symmetric(horizontal: 20, vertical: 5),
width: size.width * 0.8,
decoration: BoxDecoration(
color: kPrimaryLightColor, borderRadius: BorderRadius.circular(29)),
child: child,
);
}
}
- 在lib/widgets下创建rounded_input_field.dart文件,实现一个自定义的文本输入框。
import 'package:flutter/material.dart';
import 'package:flutterauth/constant/color_constant.dart';
import 'package:flutterauth/pages/widgets/text_field_container.dart';
class RoundedInputField extends StatelessWidget {
final String hintText;
final IconData icon;
final ValueChanged onChanged;
const RoundedInputField({
Key key,
this.hintText,
this.icon = Icons.person,
this.onChanged,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return TextFieldContainer(
child: TextField(
onChanged: onChanged,
cursorColor: kPrimaryColor,
decoration: InputDecoration(
icon: Icon(icon,color: kPrimaryColor,),
hintText: hintText,
border: InputBorder.none,
),
),
);
}
}
- 在lib/widgets下创建rounded_password_field.dart文件,实现一个人密码输入框。
import 'package:flutter/material.dart';
import 'package:flutterauth/constant/color_constant.dart';
import 'package:flutterauth/pages/widgets/text_field_container.dart';
class RoundedPasswordField extends StatelessWidget {
final ValueChanged onChanged;
const RoundedPasswordField({
Key key,
this.onChanged,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return TextFieldContainer(
child: TextField(
obscureText: true,
onChanged: onChanged,
cursorColor: kPrimaryColor,
decoration: InputDecoration(
icon: Icon(
Icons.lock,
color: kPrimaryColor,
),
hintText: "Password",
border: InputBorder.none,
suffixIcon: Icon(
Icons.visibility,
color: kPrimaryColor,
),
),
),
);
}
}
- 在lib/widgets下创建account_check.dart文件,实现文案组件。
import 'package:flutter/material.dart';
import 'package:flutterauth/constant/color_constant.dart';
class AccountCheck extends StatelessWidget {
final bool login;
final Function press;
const AccountCheck({
Key key,
this.login = true,
this.press,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
login ? "Don't have an Account ? " : "Already have an Account ? ",
style: TextStyle(color: kPrimaryColor),
),
GestureDetector(
onTap: press,
child: Text(
login ? "Sign Up" : "Sign In",
style: TextStyle(
color: kPrimaryColor,
fontWeight: FontWeight.bold,
),
),
)
],
);
}
}
- 在login/components目录下创建body.dart实现前景层渲染。
import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:flutterauth/pages/login/components/background.dart';
import 'package:flutterauth/pages/signup/sign_up.dart';
import 'package:flutterauth/pages/widgets/account_check.dart';
import 'package:flutterauth/pages/widgets/rounded_button.dart';
import 'package:flutterauth/pages/widgets/rounded_input_field.dart';
import 'package:flutterauth/pages/widgets/rounded_password_field.dart';
class Body extends StatelessWidget {
const Body({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Background(
child: SingleChildScrollView(
child: Column(
children: [
Text(
"LOGIN",
style: TextStyle(fontWeight: FontWeight.bold),
),
SizedBox(
height: size.height * 0.03,
),
SvgPicture.asset(
"assets/icons/login.svg",
height: size.height * 0.35,
),
SizedBox(
height: size.height * 0.03,
),
RoundedInputField(
hintText: "Your Email",
onChanged: (value) {},
),
RoundedPasswordField(
onChanged: (value) {},
),
RoundedButton(
text: "LOGIN",
press: () {},
),
SizedBox(
height: size.height * 0.03,
),
AccountCheck(
press: () {
},
)
],
),
),
);
}
}
- 在login目录下创建login.dart文件,渲染整个登录页面。
import 'package:flutter/material.dart';
import 'package:flutterauth/pages/login/components/body.dart';
class Login extends StatelessWidget{
@override
Widget build(BuildContext context) {
return Scaffold(
body: Body(),
);
}
}
- 修改lib/pages/welcome/components/body.dart文件,修改登录按钮的点击事件,添加登录页的路由。
RoundedButton(
text: "SIGN IN",
press: (){
Navigator.push(context, MaterialPageRoute(
builder: (context){
return Login();
}
));
},
),
- 运行APP,并点击登录按钮,会跳转到登录页面。
实现注册页
- 在pages目录下创建signup目录,在signup下创建components目录。
- 注册页面也是采用背景层和前景层的布局方式。
- 在components目录下创建background.dart文件实现背景层。
import 'package:flutter/material.dart';
class Background extends StatelessWidget {
final Widget child;
const Background({
Key key,
@required this.child,
}) : super(key: key);
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
height: size.height,
width: double.infinity,
child: Stack(
alignment: Alignment.center,
children: [
Positioned(
top: 0,
left: 0,
child: Image.asset(
"assets/images/signup_top.png",
width: size.width * 0.35,
),
),
Positioned(
bottom: 0,
left: 0,
child: Image.asset(
"assets/images/main_bottom.png",
width: size.width * 0.25,
),
),
child,
],
),
);
}
}
- 在components目录下创建or_deivider.dart文件,实现分割线。
import 'package:flutter/material.dart';
import 'package:flutterauth/constant/color_constant.dart';
class OrDivider extends StatelessWidget {
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Container(
margin: EdgeInsets.symmetric(vertical: size.height * 0.02),
width: size.width * 0.8,
child: Row(
children: [
buildDivider(),
Padding(
padding: const EdgeInsets.symmetric(horizontal: 10),
child: Text(
"OR",
style: TextStyle(
color: kPrimaryColor,
fontWeight: FontWeight.w600,
),
),
),
buildDivider(),
],
),
);
}
Expanded buildDivider() {
return Expanded(
child: Divider(
color: Color(0xffd9d9d9),
height: 1.5,
),
);
}
}
- 在components目录下创建socal_icon.dart文件,用于实现社交icon渲染。
import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:flutterauth/constant/color_constant.dart';
class SocalIcon extends StatelessWidget {
final String iconSrc;
final Function press;
const SocalIcon({
Key key,
this.press,
this.iconSrc,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return GestureDetector(
onTap: press,
child: Container(
margin: EdgeInsets.symmetric(horizontal: 10),
padding: EdgeInsets.all(20),
decoration: BoxDecoration(
border: Border.all(width: 2, color: kPrimaryLightColor),
shape: BoxShape.circle,
),
child: SvgPicture.asset(
iconSrc,
height: 20,
width: 20,
),
),
);
}
}
- 在components目录下创建body.dart文件实现前景层。
import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:flutterauth/pages/login/login.dart';
import 'package:flutterauth/pages/signup/components/background.dart';
import 'package:flutterauth/pages/signup/components/or_divider.dart';
import 'package:flutterauth/pages/signup/components/socal_icon.dart';
import 'package:flutterauth/pages/widgets/account_check.dart';
import 'package:flutterauth/pages/widgets/rounded_button.dart';
import 'package:flutterauth/pages/widgets/rounded_input_field.dart';
import 'package:flutterauth/pages/widgets/rounded_password_field.dart';
class Body extends StatelessWidget {
@override
Widget build(BuildContext context) {
Size size = MediaQuery.of(context).size;
return Background(
child: SingleChildScrollView(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
"SIGNUP",
style: TextStyle(fontWeight: FontWeight.bold),
),
SizedBox(
height: size.height * 0.03,
),
SvgPicture.asset(
"assets/icons/signup.svg",
height: size.height * 0.35,
),
RoundedInputField(
hintText: "Your Email",
onChanged: (value) {},
),
RoundedPasswordField(
onChanged: (value) {},
),
RoundedButton(
text: "SIGNUP",
press: () {},
),
SizedBox(
height: size.height * 0.03,
),
AccountCheck(
login: false,
press: () {
},
),
OrDivider(),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
SocalIcon(
iconSrc: "assets/icons/facebook.svg",
press: () {},
),
SocalIcon(
iconSrc: "assets/icons/twitter.svg",
press: () {},
),
SocalIcon(
iconSrc: "assets/icons/google-plus.svg",
press: () {},
)
],
)
],
),
),
);
}
}
- 在signup目录下创建sign_up.dart文件,渲染整个注册页面。
import 'package:flutter/material.dart';
import 'components/body.dart';
class SignUp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Body(),
);
}
}
- 修改lib/pages/welcome/components/body.dart文件,为注册按钮添加点击事件,添加注册页的路由。
RoundedButton(
text:"SIGN UP",
color: kPrimaryLightColor,
textColor: Colors.black,
press:(){
Navigator.push(context, MaterialPageRoute(
builder: (context){
return SignUp();
}
));
},
)
-
运行App,点击注册按钮即可进入注册页面。
注册页和登录页跳转
- 修改lib/pages/login/components/body.dart文件,添加跳转注册页逻辑。
AccountCheck(
press: () {
Navigator.push(context, MaterialPageRoute(builder: (context) {
return SignUp();
}));
},
)
- 修改lib/pages/signup/components/body.dart文件,添加跳转登录页逻辑。
AccountCheck(
login: false,
press: () {
Navigator.push(context, MaterialPageRoute(builder: (context) {
return Login();
}));
},
)
- 运行App,可以在注册页和登录页互相跳转。