前言
使用Flutter开发一款App是一件非常愉快的事情，其出色的性能、跨多端以及数量众多的原生组件都是我们选择Flutter的理由！今天我们就来使用Flutter开发一款电影类的App，先看下App的截图。
从main.dart开始
在Flutter里main.dart是应用开始的地方:
import 'package:flutter/material.dart';
import 'package:movie/utils/router.dart' as router;
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: '电影',
theme: ThemeData(
primarySwatch: Colors.blue,
),
onGenerateRoute: router.generateRoute,
initialRoute: '/',
);
}
}
一般的，在Flutter中管理路由有两种方式，一种是直接使用Navigator.of(context).push()，这种方式比较适合非常简单的应用，随着应用的不断发展，逻辑越来越多，推荐使用具名路由来管理应用，本文也是使用的这种方式。直接将路由挂在MaterialApp的onGenerateRoute字段上即可，具体的路由定义放在了单独的文件中进行管理utils/router.dart:
import 'package:flutter/material.dart';
import 'package:movie/screens/home.dart';
import 'package:movie/screens/detail.dart';
import 'package:movie/screens/videoPlayer.dart';
Route<dynamic> generateRoute(RouteSettings settings) {
switch (settings.name) {
case '/':
return MaterialPageRoute(builder: (context) => Home());
case 'detail':
var arguments = settings.arguments;
return MaterialPageRoute(
builder: (context) => MovieDetail(id: arguments));
case 'video':
var arguments = settings.arguments;
return MaterialPageRoute(
builder: (context) => VideoPage(url: arguments));
default:
return MaterialPageRoute(builder: (context) => Home());
}
}
真是像极了前端的路由定义，先将组件import进来，然后在各自的路由中return即可。
首页
在首页中使用TabBar来展示"正在热映"和"TOP250":
import 'package:flutter/material.dart';
import 'package:movie/screens/hot.dart';
class Home extends StatefulWidget {
Home({Key key}) : super(key: key);
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> with SingleTickerProviderStateMixin {
TabController _tabController;
@override
void initState() {
super.initState();
_tabController = TabController(vsync: this, initialIndex: 0, length: 2);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: TabBar(
controller: _tabController,
tabs: <Widget>[
Tab(text: '正在热映'),
Tab(text: 'TOP250'),
],
),
),
body: TabBarView(
controller: _tabController,
children: <Widget>[
Hot(),
Hot(history: true),
],
),
);
}
}
两个页面的布局是一样的，只有数据是不同的，所以我们复用这个页面Hot,传入history参数来代表是否为Top250页面
复用的Hot组件
import 'package:flutter/material.dart';
import 'package:movie/utils/api.dart' as api;
import 'package:movie/widgets/movieItem.dart';
class Hot extends StatefulWidget {
final bool history;
Hot({Key key, this.history = false}) : super(key: key);
_HotState createState() => _HotState();
}
class _HotState extends State<Hot> with AutomaticKeepAliveClientMixin {
List _movieList = [];
int start = 0;
int total = 0;
ScrollController _scrollController = ScrollController();
@override
void initState() {
super.initState();
_scrollController.addListener(() {
if (_scrollController.position.pixels ==
_scrollController.position.maxScrollExtent) {
getMore();
}
});
this.query(init: true);
}
query({bool init = false}) async {
Map res = await api.getMovieList(
history: widget.history, start: init ? 0 : this.start);
var start = res['start'];
var total = res['total'];
var subjects = res['subjects'];
setState(() {
if (init) {
this._movieList = subjects;
} else {
this._movieList.addAll(subjects);
}
this.start = start + 10;
this.total = total;
});
}
Future<Null> _onRefresh() async {
await this.query(init: true);
}
getMore() {
if (start < total) {
query();
}
}
@override
bool get wantKeepAlive => true;
@override
Widget build(BuildContext context) {
super.build(context);
return RefreshIndicator(
onRefresh: _onRefresh,
child: ListView.builder(
controller: _scrollController,
itemCount: this._movieList.length,
itemBuilder: (BuildContext context, int index) =>
MovieItem(data: this._movieList[index]),
),
);
}
}
电影的详情页面
点击单条电影时使用Navigator.pushNamed(context, 'detail', arguments: data['id']);即可跳转详情页，在详情页中通过id再请求接口获取详情:
import 'package:flutter/material.dart';
import 'package:movie/widgets/detail/detailTop.dart';
import 'package:movie/widgets/detail/rateing.dart';
import 'package:movie/widgets/detail/actors.dart';
import 'package:movie/widgets/detail/photos.dart';
import 'package:movie/widgets/detail/comments.dart';
import 'package:movie/utils/api.dart' as api;
class MovieDetail extends StatefulWidget {
final id;
MovieDetail({Key key, this.id}) : super(key: key);
_MovieDetailState createState() => _MovieDetailState();
}
class _MovieDetailState extends State<MovieDetail> {
var _data = {};
@override
void initState() {
super.initState();
this.init();
}
init() async {
var res = await api.getMovieDetail(widget.id);
setState(() {
_data = res;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: _data.isEmpty
? Center(child: CircularProgressIndicator(),)
: SafeArea(
child: Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: ListView(
scrollDirection: Axis.vertical,
children: <Widget>[
MovieDetailTop(data: _data),
Rate(count: _data['ratings_count'], rating: _data['rating']),
Container(padding: EdgeInsets.all(10),child: Text(_data['summary'])),
Actors(directors: _data['directors'], casts: _data['casts']),
Photos(photos: _data['photos'],),
Comments(comments: _data['popular_comments']),
],
),
),
),
);
}
}
在详情页面中，我们封装了一些组件，这样能让项目更加容易阅读和维护，组件的具体实现就不详细介绍了，都是一些常用的原生组件，这些组件分别是：
真实数据来自哪里？
应用中的数据都是从豆瓣开发者api中拉取的，分别是，正在热映in_theaters，top250top250和电影详情subject/id三个接口,请求这些接口是需要apikey的，为了大家能方便请求数据，我将apikey上传到了github上，还请大家温柔点，不要将这个apikey干爆了。
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，谢谢大家对的支持。
