home: HomePage(), )); } class HomePage extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('Home Page'), ), body: Center( child: ElevatedButton( child: Text('Go to New Page'), onPressed: () { ...
// to the screen. RaisedButton( child: Text("Navigate to a named that accepts arguments"), onPressed: () { // When the user taps the button, navigate to a named route // and provide the arguments as an optional parameter. Navigator.pushNamed( context, PassArgumentsScreen.routeName, argum...
IconButton( // 1 icon: Icon(_isFavorited ? Icons.favorite : Icons.favorite_border), iconSize: 30, // 2 color: Colors.red[400], onPressed: () { // 3 setState(() { _isFavorited = !_isFavorited; }); }, ) Here’s how the new state works: First, it checks if the user ...
which will be the first thing that Flutter runs in the whole app. In the main method, we execute flutter’s inbuilt function runApp from flutter’s widget library which inflates the given widget/class and attaches it to the screen, and we pass the...
//Pass the onPressed parameter, which is essentially the equivalent of onClick// onPressed: _incrementCounter, tooltip: 'Increment', child: new Icon(Icons.add), ), ); } } The easiest way to check whether a widget supports event detection, is to review its documentation. For example, the...
onPressed: () { _controller.text = "newText"; //每次修改内容的时候需要再手动修改selection _controller.selection = TextSelection.fromPosition( TextPosition(offset: _controller.text.length)); }, child: Text("click me"), ), TextField(
onPressed: () { Navigator.push( context, MaterialPageRoute(builder: (context) => Settings()), ); }, ) ], ), body: ... ); } }Code language:Dart(dart) With this code in place, when we reload our app we should see the localized value of our tooltip in theWidget Inspector. ...
If the Widget supports event detection, pass a function to it and handle it in the function. For example, the RaisedButton has anonPressedparameter: @override Widget build(BuildContext context) { return new RaisedButton( onPressed: () { ...
watch(counterStateProvider); return ElevatedButton( // 2. use the value child: Text('Value: $counter'), // 3. change the state inside a button callback onPressed: () => ref.read(counterStateProvider.notifier).state++, ); } }
onPressed: () async { final now = DateTime.now(); final result = await showDatePicker( context: context, initialDate: now, firstDate: now.subtract( const Duration( days: 90, ), ), lastDate: now); if (result != null) { setState(() { ...