6.完整的代码
class UpdaterPage extends StatefulWidget { final Widget child; const UpdaterPage(this.child); @override UpdatePagerState createState() => UpdatePagerState(); } class UpdatePagerState extends State<UpdaterPage> { var _serviceVersionCode, _serviceVersionName, _serviceVersionPlatform, _serviceVersionApp; @override void initState() { super.initState(); //每次打开APP获取当前时间戳 var timeEnd = DateTime.now().millisecondsSinceEpoch; //获取"Later"保存的时间戳 var timeStart = SpUtil.getInt(Constants.timeStart); if (timeStart == 0) {//第一次打开APP时执行"版本更新"的网络请求 _getNewVersionAPP(); } else if (timeStart != 0 && timeEnd - timeStart >= 24 * 60 * 60 * 1000) { //如果新旧时间戳的差大于或等于一天，执行网络请求 _getNewVersionAPP(); } } //执行版本更新的网络请求 _getNewVersionAPP() async { DioUtil.getInstance().get(context, url).then((response) { if (response != null) { setState(() { var data = response.data; _serviceVersionCode = data["versionCode"].toString();//版本号 _serviceVersionName = data["versionName"].toString();//版本名称 _serviceVersionPlatform = data["versionPlatform"].toString();//版本平台 _serviceVersionApp = data["versionApp"].toString();//下载的URL _checkVersionCode(); }); } }); } //检查版本更新的版本号 _checkVersionCode() async { PackageInfo packageInfo = await PackageInfo.fromPlatform(); String _currentVersionCode = packageInfo.version; int serviceVersionCode = int.parse(_serviceVersionCode); //String -> int int currentVersionCode = int.parse(_currentVersionCode); //String -> int if (serviceVersionCode > currentVersionCode) { _showNewVersionAppDialog();//弹出对话框 } } //弹出"版本更新"对话框 Future<void> _showNewVersionAppDialog() async { if (_serviceVersionPlatform == "android") { return showDialog<void>( context: context, barrierDismissible: false, builder: (BuildContext context) { return AlertDialog( title: new Row( children: <Widget>[ new Image.asset("images/ic_launcher_icon.png", height: 35.0, width: 35.0), new Padding( padding: const EdgeInsets.fromLTRB(30.0, 0.0, 10.0, 0.0), child: new Text("项目名称", style: dialogButtonTextStyle)) ], ), content: new Text( \'版本更新\', style: dialogTextStyle), actions: <Widget>[ new FlatButton( child: new Text(\'Later\', style: dialogButtonTextStyle), onPressed: () { Navigator.of(context).pop(); var timeStart = DateTime.now().millisecondsSinceEpoch; DataUtil.saveCurrentTimeMillis(timeStart);//保存当前的时间戳 }, ), new FlatButton( child: new Text(\'DownLoad\', style: dialogButtonTextStyle), onPressed: () { //https://play.google.com/store/apps/details?id=项目包名 launch(_serviceVersionApp);//到Google Play 官网下载 Navigator.of(context).pop(); }, ) ], ); }); }else{ //iOS return showDialog<void>( context: context, barrierDismissible: false, builder: (BuildContext context) { return CupertinoAlertDialog( title: new Row( children: <Widget>[ new Image.asset("images/ic_launcher_icon.png", height: 35.0, width: 35.0), new Padding( padding: const EdgeInsets.fromLTRB(30.0, 0.0, 10.0, 0.0), child: new Text(Strings.new_version_title, style: dialogButtonTextStyle)) ], ), content: new Text( "New version v$_serviceVersionName is available. " + Strings.new_version_dialog_content, style: dialogTextStyle), actions: <Widget>[ new CupertinoDialogAction( child: new Text(Strings.new_version_button_later, style: dialogButtonTextStyle), onPressed: () { Navigator.of(context).pop(); var timeStart = DateTime.now().millisecondsSinceEpoch; DataUtil.saveCurrentTimeMillis(timeStart);//保存当前的时间戳 }, ), new CupertinoDialogAction( child: new Text(Strings.new_version_button_download, style: dialogButtonTextStyle), onPressed: () { //_serviceVersionApp="http://itunes.apple.com/cn/lookup?id=项目包名" launch(_serviceVersionApp);//到APP store 官网下载 Navigator.of(context).pop(); }, ) ], ); }); } } @override Widget build(BuildContext context) => widget.child; }