目录
一、集成flutter_swiper和cached_network_image
二、flutter_swiper
三、图片缓存
四、整体代码
五、flutter run
一、集成flutter_swiper和cached_network_image
pubspec.yaml 中 添加flutter_swiper : ^1.1.6和 cached_network_image: ^1.0.0,并同步 flutter packages get 。
在相应的 .dart 文件中添加引用import 'package:flutter_swiper/flutter_swiper.dart'和import 'package:cached_network_image/cached_network_image.dart'。
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: ^0.1.2
dio: ^2.1.10
fluttertoast: ^3.1.0
flutter_swiper: ^1.1.6
cached_network_image: ^1.0.0
二、flutter_swiper
可以设置滚动方向,设置为Axis.vertical如果需要垂直滚动。多种布局方式,无限轮播,Android和IOS双端适配。
ConstrainedBox(
child: Swiper(
outer: false,
itemBuilder: (c, i) {
if(swiperDataList!=null){
return CachedNetworkImage(
imageUrl: "${swiperDataList[i]}",
placeholder: (context, url) => new CircularProgressIndicator(),
errorWidget: (context, url, error) => new Icon(Icons.error),
);
}
},
pagination:
new SwiperPagination(margin: new EdgeInsets.all(5.0)),
itemCount: swiperDataList == null ? 0 : swiperDataList.length,
),
constraints:
new BoxConstraints.loose(new Size(MediaQuery.of(context).size.width, 180.0)))
三、图片缓存
CachedNetworkImage缓存网络图片,加载时还支持占位图和淡入淡出图片。
CachedNetworkImage(
imageUrl: "${listData[index]['images']['small']}",
placeholder: (context, url) => new CircularProgressIndicator(),
errorWidget: (context, url, error) => new Icon(Icons.error),
fit: BoxFit.fill,
)
四、整体代码
import 'package:flutter/material.dart';
import 'package:flutter_swiper/flutter_swiper.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'util/YFHttp.dart';
class IndexPage extends StatefulWidget {
_IndexPageState createState() => _IndexPageState();
}
class _IndexPageState extends State<IndexPage> {
List listData;
List swiperDataList=["https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1562723625662&di=bc7be59dd27706ea65ea33a94c209477&imgtype=0&src=http%3A%2F%2Fpic.58pic.com%2F58pic%2F12%2F40%2F43%2F18958PICYpQ.jpg",
"https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1562723734494&di=864f7b85f900f0b68e8bc08f1c078eed&imgtype=0&src=http%3A%2F%2Fb-ssl.duitang.com%2Fuploads%2Fblog%2F201511%2F02%2F20151102140204_WUSwE.jpeg",
"https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1562723821634&di=e04d14690229411a560ccc6cf0e10f6a&imgtype=0&src=http%3A%2F%2Fpic.58pic.com%2F58pic%2F15%2F01%2F96%2F56N58PICVWw_1024.jpg"];
void _loadData() async {
var result = await YFHttp.request('/v2/movie/in_theaters',
data: {
'apikey': "0b2bdeda43b5688921839c8ecb20399b",
},
method: YFHttp.GET);
setState(() {
listData = result['subjects'];
});
}
@override
void initState() {
this._loadData();
super.initState();
}
Widget _getItems(context, index) {
if (listData.length > 0) {
return ListTile(
title: Text(listData[index]["title"]),
subtitle: Text(listData[index]["mainland_pubdate"]),
leading: CachedNetworkImage(
imageUrl: "${listData[index]['images']['small']}",
placeholder: (context, url) => new CircularProgressIndicator(),
errorWidget: (context, url, error) => new Icon(Icons.error),
fit: BoxFit.fill,
)
);
} else {
return ListTile();
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('轮播图'),
),
body: Column(
children: <Widget>[
ConstrainedBox(
child: Swiper(
outer: false,
itemBuilder: (c, i) {
if(swiperDataList!=null){
return CachedNetworkImage(
imageUrl: "${swiperDataList[i]}",
placeholder: (context, url) => new CircularProgressIndicator(),
errorWidget: (context, url, error) => new Icon(Icons.error),
);
}
},
pagination:
new SwiperPagination(margin: new EdgeInsets.all(5.0)),
itemCount: swiperDataList == null ? 0 : swiperDataList.length,
),
constraints:
new BoxConstraints.loose(new Size(MediaQuery.of(context).size.width, 180.0))),
Expanded(
child: ListView.builder(
itemCount: listData == null ? 0 : listData.length,
itemBuilder: this._getItems),
)
],
),
);
}
}