I am trying to navigate from one screen to another with route. When I hit the button for the page to move to the route provided I get the error I/flutter ( 8790): Another exception was thrown: There are multiple heroes that share the same tag within a subtree. Here’s the code: Routes: <String, WidgetBuilder>{ … Read more
I’m wondering what the recommended way of passing data to a stateful widget, while creating it, is. The two styles I’ve seen are: class ServerInfo extends StatefulWidget { Server _server; ServerInfo(Server server) { this._server = server; } @override State<StatefulWidget> createState() => new _ServerInfoState(_server); } class _ServerInfoState extends State<ServerInfo> { Server _server; _ServerInfoState(Server server) { this._server … Read more
I am configuring the Flutter SDK on my Linux Ubuntu 16.04 (Xenial Xerus) system. Why am I getting the following error when I run the flutter doctor? I have specified both PATHS for flutter and dart in the .bashrc file, but I get this error when I run flutter doctor: Doctor summary (to see all details, … Read more
Any solution to solve this problem? Stacktrace: [VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: ServicesBinding.defaultBinaryMessenger was accessed before the binding was initialized. If you’re running an application and need to access the binary messenger before `runApp()` has been called (for example, during plugin initialization), then you need to explicitly call the `WidgetsFlutterBinding.ensureInitialized()` first. If you’re running a test, you … Read more
I’d like to execute a function after a certain delay after my Widget is built. What’s the idiomatic way of doing this in Flutter? What I’m trying to achieve: I’d like to start with a default FlutterLogo Widget and then change its style property after some duration. 10 Answers 10
How can I add shadow to the widget like in the picture below? This is my current widget code. 13 Answers 13
In Android match_parent and wrap_content are used to resize the widgets automatically relative to their parent to the content the widget contains. In Flutter it seems by default all widgets are set to wrap_content, how would I change it such that I can fill its width and height to that of its parent? 13 Answers … Read more
Dart supports both named optional parameters and positional optional parameters. What are the differences between the two? Also, how can you tell if an optional parameter was actually specified? 7 Answers 7
This is my code: @override Widget build(BuildContext context) { return new Material( color: Colors.deepPurpleAccent, child: new Column( mainAxisAlignment: MainAxisAlignment.center, children:<Widget>[new GridView.count(crossAxisCount: _column,children: new List.generate(_row*_column, (index) { return new Center( child: new CellWidget() ); }),)] ) ); } Exception as follows: I/flutter ( 9925): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════ I/flutter ( 9925): The following … Read more
In Android, every single View subclass has a setVisibility() method that allows you modify the visibility of a View object There are 3 options of setting the visibility: Visible: Renders the View visible inside the layout Invisible: Hides the View, but leaves a gap that is equivalent to what the View would occupy if it … Read more
