hanyingzhong的专栏

Note about ListsLists are completely observable as are the objects within it. That way, if you add a value to a list, it will automatically rebuild the widgets that use it.You also don't need to use ".value" with lists, the amazing dart api allowed us

import 'package:flutter/material.dart'; void main() { runApp( RestartWidget( //使用StatefulWidget包装下 child: MaterialApp(), ), );} class RestartWidget extends StatefulWidget { RestartWidget({this.child}); final Widget child; .

import 'package:flutter/foundation.dart';import 'package:flutter/material.dart';class ValueListenablePage extends StatefulWidget { @override _ValueListenablePageState createState() => _ValueListenablePageState();}class _ValueListenablePageSta.

//文件下载//url 下载的地址//progressCallback 下载进度变化时的回调，用来实现进度条Future<Response> dioDownload(String url, progressCallback) async { Dio dio = Dio(); CancelToken cancelToken = CancelToken();//可以用来取消操作 String docPath = await Application.fileUtil.getDocP.

I don't want to show notification when the app is in foreground. How can I check live state of my app?4 AnswersIn your State<...> class you need to implementWidgetsBindingObserverinterface and listen for widget state changes. Something like t..

import 'dart:math';import 'package:flutter/material.dart';void main() { runApp(MyApp());}class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar.

onTap: () async { final result = await showMenu( context: context, position: RelativeRect.fromLTRB(100.0, 200.0, 100.0, 100.0),// position: RelativeRect.fromLTRB(1000.0, 1000.0, 0.0, 10.0), items: <PopupMenuItem<String>>[ .

showGeneralDialog( context: context, barrierDismissible:true, barrierLabel: '', transitionDuration: Duration(milliseconds: 200), pageBuilder: (BuildContext context, Animation<double> animation,Animation<double> secondaryAnimation) {.

IconButton( onPressed: loadAssets, icon: Icon(Icons.photo),),Future<void> loadAssets() async { List<Asset> resultList = List<Asset>(); String error = 'No Error Dectected'; try { resultList = await MultiImageP...

http://localhost/piwigo/ws.php?format=json&method=pwg.categories.getImages&cat_id=1{ "result": { "images": [ { "categories": [ { "id": 1, "page_url": "http://localhost/piwigo/picture.php?/2/c

import 'dart:io';void main() async { // ignore: prefer_typing_uninitialized_variables String connect; try { final result = await InternetAddress.lookup('DESKTOP-TR4ANSP', type: InternetAddressType.IPv4); if (result.isNotEmpty &.

扩展某个Class的能力：如果你想扩展某个系统Class的能力，不需要通过继承等的方式完成，而直接通过extension .. on 的方式进行操作。如下：/// Extends the `BuildContext` class with the ability/// to perform a lookup based on a `Bloc` type.extension BlocProviderExtension on BuildContext { /// Performs a l.

import 'dart:async';Stream get asynchronousNaturals async* { print("Begin"); int k = 0; while (k < 3) { print("Before Yield"); yield k++; } print("End");}void testAsync() { StreamSubscription subscription = asynchronousNatura.

flutter_bloclibraryClassesBloc<Event,State>{@template bloc} Takes aStreamofEventsas input and transforms them into aStreamofStatesas output. {@endtemplate}BlocBuilder<C extendsCubit<S>,S>BlocBuilderhandles building ...

import 'dart:async';Stream get asynchronousNaturals async* { print("Begin"); int k = 0; while (k < 3) { print("Before Yield"); yield k++; } print("End");}main() { StreamSubscription subscription = asynchronousNaturals.listen(.

import 'dart:async';import 'package:flutter/material.dart';import 'package:flutter_bloc/flutter_bloc.dart';/// Custom [BlocObserver] which observes all bloc and cubit instances.class SimpleBlocObserver extends BlocObserver { @override void onEv.