Flutter banner_view 轮播图的使用及实现代码

import 'package:flutter/material.dart';import 'package:banner_view/banner_view.dart';import 'Pair.dart';import 'factory/BannerItemFactory.dart';class BannerViewPage extends StatefulWidget { @override _BannerViewPageState createState() => new _BannerViewPageState();}class _BannerViewPageState extends State<BannerViewPage> { @override Widget build(BuildContext context) { return new Scaffold(  body:   new Container(   child: new Column(    children: <Widget>[    new Container(     alignment: Alignment.center,     height: 200.0,     child: this._bannerView0(),     padding: EdgeInsets.only(bottom: 10.0),    )    ],   ),   ),  ); } /** * 第一种方式 */ BannerView _bannerView0() { // 盛放图片的 List List<Pair<String, Color>> param = [  Pair.create('https://p5.ssl.qhimg.com/dm/456_209_/t01f43c5849ef5f521a.jpg', Colors.red[500]),  Pair.create('https://p.ssl.qhimg.com/t0171bb61911ebe8899.jpg', Colors.green[500]),  Pair.create('https://p.ssl.qhimg.com/t01ee77978d3a95a3ae.jpg', Colors.blue[500]), ]; return new BannerView(  BannerItemFactory.banners(param), );// return new BannerView(//  BannerItemFactory.banners(param),//  indicatorMargin: 10.0,//  indicatorNormal: new Container(//  width: 5.0,//  height: 5.0,//  decoration: new BoxDecoration(//   color: Colors.green,//   shape: BoxShape.rectangle,//  ),//  ),//  indicatorSelected: new Container(//  width: 15.0,//  height: 5.0,//  decoration: new BoxDecoration(//   color: Colors.black,//   shape: BoxShape.rectangle,//   borderRadius: new BorderRadius.all(//   new Radius.circular(5.0),//   ),//  ),//  ),//  indicatorBuilder: (context, indicator) {//  Widget cc = new Container(//   padding: new EdgeInsets.symmetric(horizontal: 20.0,),//   height: 44.0,//   width: double.infinity,//   color: Colors.grey[300],//   child: indicator,//  );//  return new Opacity(//   opacity: 0.5,//   child: cc,//  );//  },// ); } /** * 第二种方式 */ BannerView _bannerView() { var pre = 'https://raw.githubusercontent.com/yangxiaoweihn/Assets/master'; List<Pair<String, Color>> param = [  Pair.create('https://raw.githubusercontent.com/yangxiaoweihn/Assets/master/cars/car_0.jpg', Colors.red[100]),  Pair.create('https://raw.githubusercontent.com/yangxiaoweihn/Assets/master/cartoons/ct_0.jpg', Colors.green[100]),  Pair.create('https://raw.githubusercontent.com/yangxiaoweihn/Assets/master/pets/cat_1.jpg', Colors.blue[100]),  Pair.create('https://raw.githubusercontent.com/yangxiaoweihn/Assets/master/scenery/s_1.jpg', Colors.yellow[100]),  Pair.create('https://raw.githubusercontent.com/yangxiaoweihn/Assets/master/cartoons/ct_1.jpg', Colors.red[100]),//  Pair.create('$pre/cartoons/ct_1.jpg', Colors.red[100]), ]; return new BannerView(  BannerItemFactory.banners(param),  indicatorMargin: 10.0,  indicatorNormal: new Container(  width: 5.0,  height: 5.0,  decoration: new BoxDecoration(   color: Colors.green,   shape: BoxShape.rectangle,  ),  ),  indicatorSelected: new Container(  width: 15.0,  height: 5.0,  decoration: new BoxDecoration(   color: Colors.black,   shape: BoxShape.rectangle,   borderRadius: new BorderRadius.all(   new Radius.circular(5.0),   ),  ),  ),  indicatorBuilder: (context, indicator) {  Widget cc = new Container(   padding: new EdgeInsets.symmetric(horizontal: 20.0,),   height: 44.0,   width: double.infinity,   color: Colors.grey[300],   child: indicator,  );  return new Opacity(   opacity: 0.5,   child: cc,  );  }, ); }}