cross-platform

The relevant error-causing widget was Scaffold

拜拜、爱过 提交于 2021-01-01 06:48:28
问题 class _NavBarState extends State<NavBar> { int _currentIndex = 0; final List<Widget> _children = [ HomeScreen(), SignUpScreen(), ForgetPassword(), LoginScreen(), ]; void onTappedBar(int index) { setState(() { _currentIndex = index; }); } @override Widget build(BuildContext context) { return Scaffold( body: _children[_currentIndex], bottomNavigationBar: BottomNavigationBar( onTap: onTappedBar, currentIndex: _currentIndex, type: BottomNavigationBarType.fixed, items: [ BottomNavigationBarItem(

How to distribute Java Application

蹲街弑〆低调 提交于 2020-12-28 07:50:48
问题 I would like to know about the various options for distributing a Java application. I know that you can Distribute the Source Code and let users compile it themselves, or provide make files, etc.. Package it into a JAR, and have self extracting archives and (I'm sure, myriad other ways) I'm hoping for some explanations about the most common options (and one's I haven't thought of) and in particular, do they require a user to have a JVM, or can it be bundled with one - personally I'm not too

How to distribute Java Application

荒凉一梦 提交于 2020-12-28 07:50:44
问题 I would like to know about the various options for distributing a Java application. I know that you can Distribute the Source Code and let users compile it themselves, or provide make files, etc.. Package it into a JAR, and have self extracting archives and (I'm sure, myriad other ways) I'm hoping for some explanations about the most common options (and one's I haven't thought of) and in particular, do they require a user to have a JVM, or can it be bundled with one - personally I'm not too

Database indexes: A good thing, a bad thing, or a waste of time?

删除回忆录丶 提交于 2020-12-28 07:28:37
问题 Adding indexes is often suggested here as a remedy for performance problems. (I'm talking about reading & querying ONLY, we all know indexes can make writing slower). I have tried this remedy many times, over many years, both on DB2 and MSSQL, and the result were invariably disappointing. My finding has been that no matter how 'obvious' it was that an index would make things better, it turned out that the query optimiser was smarter, and my cleverly-chosen index almost always made things