Flutter 开源组件库

Flutter 提供了丰富的开源组件库，以下是一些常用的Flutter开源组件库：

1. fluttertoast: 一个可以显示toast的Flutter插件。

import 'package:fluttertoast/fluttertoast.dart';
 
Fluttertoast.showToast(
    msg: "Hello, World!",
    toastLength: Toast.LENGTH_SHORT,
    gravity: ToastGravity.BOTTOM,
    timeInSecForIosWeb: 1,
    backgroundColor: Colors.red,
    textColor: Colors.white
);

2. cached\_network\_image: 显示网络图片的时候，如果没有加载出来时，会有一个加载中的提示，加载失败时会有一个错误提示。

import 'package:cached_network_image/cached_network_image.dart';
 
CachedNetworkImage(
  placeholder: (context, url) => new CircularProgressIndicator(),
  errorWidget: (context, url, error) => new Icon(Icons.error),
  imageUrl: 'https://www.example.com/image.png',
);

3. flutter\_swiper: 一个Flutter轮播组件。

import 'package:flutter_swiper/flutter_swiper.dart';
 
Swiper(
  itemCount: 3,
  itemBuilder: (BuildContext context, int index) {
    return new Image.network("http://www.example.com/image$index.png");
  },
  pagination: new SwiperPagination(),
  control: new SwiperControl(),
)

4. flutter\_staggered\_grid\_view: 一个创建动画或者过渡效果的Flutter网格视图。

import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';
 
StaggeredGridView.count(
  crossAxisCount: 4,
  itemCount: 8,
  itemBuilder: (BuildContext context, int index) {
    return new Card(
      child: new Column(
        children: <Widget>[
          new AspectRatio(
            aspectRatio: 17 / 12,
            child: new Image.network(
              'http://www.example.com/image$index.png',
              fit: BoxFit.fill,
            ),
          ),
          new Container(
            padding: const EdgeInsets.all(8.0),
            child: new Text('Staggered Grid View Example'),
          ),
        ],
      ),
    );
  },
  staggeredTileBuilder: (int index) =>
      new StaggeredTile.count(2, index.isEven ? 2 : 1),
)

5. flutter\_html\_view: 一个可以渲染HTML的Flutter组件。

import 'package:flutter_html_view/flutter_html_view.dart';
 
FlutterHtmlView(
  htmlData: "<h1>Hello, World!</h1>",
)

6. flutter\_calendar: 一个日历组件。

import 'package:flutter_calendar/flutter_calendar.dart';
 
CalendarController _calendarController;
 
Widget build(BuildContext context) {
  _calendarController = CalendarController();
 
  return Container(
    child: Ca