从 Flutter 2.0 开始学 - 路由封装、界面跳转、登录注册 UI

欢迎、引导	登录、注册	主页

Flutter 路由跳转

界面跳转 push 相当于是一个入栈操作

界面返回 pop 相当于是一个出栈操作

封装 Fluro 路由工具类

fluro 提供了对路由入栈和出栈，在跳转和返回界面也可以设置对应参数控制（动画、时间、入栈方向、是否替换/清空）

Android activity startActivity

iOS pushViewController popViewController

封装 navigate_util.dart

• core -> utils -> navigate_util.dart

import 'package:fluro/fluro.dart';
import 'package:moose_app/ui/routers/application.dart';
class ATHNavigator {
  // 入栈
  static push(context, path) {
    ATHApplication.router
        .navigateTo(context, path, transitionDuration: Duration(seconds: 1));
  }
  // 出栈
  static pop(context) {
    ATHApplication.router.pop(context);
  }
  // 从右边入栈
  static pushFromRight(context, path) {
    ATHApplication.router
        .navigateTo(context, path, transition: TransitionType.inFromRight);
  }
  // 1s 从右边入栈
  static pushFromRightDuration(context, path) {
    ATHApplication.router.navigateTo(context, path,
        transition: TransitionType.inFromRight,
        transitionDuration: Duration(seconds: 1));
  }
  // 入栈 谈入动画
  static pushFadeIn(context, path) {
    ATHApplication.router.navigateTo(context, path,
        transition: TransitionType.fadeIn,
        transitionDuration: Duration(seconds: 1));
  }
  // 入栈替换，clearStack 是否清空栈
  static pushReplace(context, path, {clearStack: false}) {
    ATHApplication.router.navigateTo(context, path,
        replace: true,
        clearStack: clearStack,
        transition: TransitionType.fadeIn,
        transitionDuration: Duration(seconds: 0));
  }
  // 入栈替换 谈入
  static pushFadeInReplace(context, path) {
    ATHApplication.router.navigateTo(context, path,
        replace: true,
        transition: TransitionType.fadeIn,
        transitionDuration: Duration(seconds: 0));
  }
}

登录界面

• 创建登录界面

  • lib/ui/screens/login

ATHLoginScreen

• login_screen.dart

import 'package:flutter/material.dart';
import 'login_body.dart';
class ATHLoginScreen extends StatelessWidget {
  static final String routeName = "app://login";
  ATHLoginScreen({Key key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    // flutter material 自带脚手架
    return Scaffold(
      body: ATHLoginBody(),
    );
  }
}

Scaffold Flutter 自带组件，可以设置 appBar、floatingActionButton、drawer …，用于快速构建展示视图

ATHLoginBody

• login_body.dart

....
import 'login_background.dart';
class ATHLoginBody extends StatefulWidget {
  ATHLoginBody({Key key}) : super(key: key);
  @override
  _LoginBodyState createState() => _LoginBodyState();
}
class _LoginBodyState extends State<ATHLoginBody> {
  final TextEditingController _usernameController = TextEditingController();
  final TextEditingController _passwordController = TextEditingController();
  @override
  void initState() {
    super.initState();
    _usernameController.text = "江景";
    _passwordController.text = "123";
  }
  void _onLoginButtonPressed() async {
    ATHNavigator.pushReplace(context, ATHMainScreen.routeName,
        clearStack: true);
  }
  @override
  Widget build(BuildContext context) {
    return GestureDetector(
        onTap: () {
          ATHFocusUtil.requestFocus(context);
        },
        child: ATHLoginBackground(
          child: SingleChildScrollView(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Image.asset(
                  'assets/images/login.png',
                  height: 400.h,
                ),
                ATHAuthAccountInput(
                  hintText: "账号",
                  controller: _usernameController,
                  // onChanged: (value) => {print('$value')},
                ),
                ATHAuthPasswordInput(
                  hintText: "密码",
                  controller: _passwordController,
                  // onChanged: (value) => {},
                ),
                ATHAuthButton(
                  text: "登录",
                  press: () {
                    ATHFocusUtil.requestFocus(context);
                    _onLoginButtonPressed();
                  },
                ),
                ATHUserAlready(
                  login: true,
                  press: () {
                    ATHNavigator.pushReplace(
                        context, ATHRegisterScreen.routeName);
                  },
                ),
              ],
            ),
          ),
        ));
  }
}

GestureDetector ： Flutter 中手势事件

TextEditingController ： 文本编辑控制器，可以监听文本框改变

ATHFocusUtil ： 获取焦点工具类

SingleChildScrollView ：Flutter 组件单个子组件滚动容器

ATHLoginBackground

• login_background.dart

import 'package:flutter/material.dart';
class ATHLoginBackground extends StatelessWidget {
  final Widget child;
  const ATHLoginBackground({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: <Widget>[
          child,
        ],
      ),
    );
  }
}

Container: Flutter 容器组件

MediaQuery.of(context).size 获取屏幕尺寸

Stack：容器组件，可以根据 Position 放置不同位置子组件

注册界面

和登录界面基本一致，只需要把封装好的容器一个个按照顺序摆放就行