dart-2

问题 I am using banklist in stateful widget. passing list to pageState using List<Bank> bankLists = this.widget.bankLists; Que 1. Why I am getting error at gradientcolor: gradientBankCard("FFB74093","FFB74093")) that only static members can be accessed in initializer? Que 2. How to pass const Data to gradientBankCard method . for Example I want to pass Color.fromRGBO(220, 132, 58, 1.0) to Arguments that gives error to. I List<Bank> bankLists = [ Bank( id: "1", name: "B1", loanAmount: "₹ 250000",

来源： https://stackoverflow.com/questions/52794266/pub-global-activate-command-home-pub-cache-bin-not-on-path

来源： https://stackoverflow.com/questions/52442724/boxconstraints-forces-an-infinite-width

来源： https://stackoverflow.com/questions/54933145/null-aware-function-call

问题 i am doing screen change like this iam listing for stream and when it emit i change the screen @override void initState() { super.initState(); appBloc.error.listen((data) { _scaffoldKey.currentState.showSnackBar(new SnackBar(content: new Text(data))); }); appBloc.success.listen((_) => goToDashBoardScreen(context)); } and doToDashBoardScreen look like this Navigator.pushReplacement(context, new SlideRightRoute(widget: DashBoardScreen())); but i am getting error like this but i change the page.

问题 My flutter app is using firebase as a backend but I need to store media files (photos & videos) in my s3 bucket. The mission is to upload the media retrieved from the image picker into s3 & get back the url, which can then be stored as a string in my firebase database. The problem is a scarcity of aws libraries or api for dart 2. I found 3 in pub, but 2 of them were incompatible with dart 2 & 1 was under development. Has anyone implemented this in flutter using dart 2? Any suggestions are

问题 I am getting exception when I trying to navigate from one view to another in flutter app. I/flutter ( 2199): ══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════ I/flutter ( 2199): The following assertion was thrown while handling a gesture: I/flutter ( 2199): Could not find a generator for route "home-page" in the _MaterialAppState. 回答1: Use Navigator.push(context, new MaterialPageRoute( builder: (context) => new MyHomePage()) ); Instead of

问题 I am having trouble calling on the Twitter api in my Flutter app. I have used the twitter sign in library to get my token and secret token, and I have my consumer and consumer secret. But I am unable to form an https request correctly. I have tried using an Oauth2 client as well as a straight request and neither has worked. I found this repo with a dart 1 Twitter and Oauth implementation, but I have been unable to figure out how to convert this to Dart 2. All help is greatly appreciated. Edit

问题 I am using chartjs (with the dart interface https://pub.dartlang.org/packages/chartjs) and trying to make it deferred by injecting a <script src="chartjs.js"></script> into the head section and awaiting it's load event to then use the lib. I am getting this exception: Cannot read property 'Chart' of undefined. It does not happen when the script is within the head of the html before dart. So, is it possible to load a JS lib after Dart loaded? 回答1: this is a problem in DDC. It addeds require.js

问题 I have initially empty list of Widget in Column. Now on Other widget click I am adding new Custom Widget in _contactItems Column( children: _contactItems, ) List<Widget> _contactItems = new List<CustomWidget>(); _contactItems.add(newCustomWidget(value)); Now Suppose I have 6 Records (6 Custom Widgets in Column). I am trying to remove index wise records (Example. I am removing 3rd record then 1st record. Column Widgets (dynamic widgets) should be updated as _contactItems updating in setState()