单击
StatelessWidget该类并使用
option + enter（或者，
cmd + .如果您在macOS上使用VS
Code），您将看到一个IDE选项，可以帮助您完成此操作。
这是工作代码。
class DetailPage extends StatefulWidget { final Activity activity; DetailPage({Key key, this.activity}) : super(key: key); @override _DetailPageState createState() => _DetailPageState();}class _DetailPageState extends State<DetailPage> { bool _tracking = false, _mapped = false; // you need this String _schedule; @override Widget build(BuildContext context) { final levelIndicator = Container( child: Container( child: LinearProgressIndicator(backgroundColor: Color.fromRGBO(209, 224, 224, 0.2), value: 2.0, valueColor: AlwaysStoppedAnimation(Colors.green)), ), ); final topContentText = Column( crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[ SizedBox(height: 120.0), Container( width: 90.0, child: Divider(color: Colors.green), ), SizedBox(height: 10.0), Text( widget.activity.activityName, style: TextStyle(color: Colors.white, fontSize: 45.0), ), SizedBox(height: 30.0), Row( mainAxisAlignment: MainAxisAlignment.start, children: <Widget>[ Expanded( flex: 6, child: Padding( padding: EdgeInsets.only(left: 10.0), child: Text("Last Run: 3-2-19n" + "Last Avg Strain: 34%n" + "Last Run Time: 00:45:23",style: TextStyle(color: Colors.white), ))), // Expanded(flex: 1, child: newRow) ], ), ], ); final topContent = Stack( children: <Widget>[ Container( height: MediaQuery.of(context).size.height * 0.45, padding: EdgeInsets.all(40.0), width: MediaQuery.of(context).size.width, decoration: BoxDecoration( gradient: LinearGradient( begin: Alignment.centerLeft, end: Alignment.centerRight, colors: [Color.fromRGBO(33, 147, 176, 100), Color.fromRGBO(109, 213, 237, 100)], ), ), child: Center( child: topContentText, ), ), Positioned( left: 235.0, top: 180.0, child: InkWell( onTap: () { Navigator.pop(context); }, child: CircleAvatar( radius: 80.0, backgroundColor: Colors.white, ), ), ), Positioned( left: 8.0, top: 60.0, child: InkWell( onTap: () { Navigator.pop(context); }, child: Icon(Icons.arrow_back, color: Colors.white), ), ) ], ); final bottomContentText = Text( "Config:", style: TextStyle(fontSize: 18.0), ); final mappedCheckbox = CheckboxListTile( title: Text("Mapped"), value: _mapped, onChanged: (newValue) => setState(() => _mapped = newValue), controlAffinity: ListTileControlAffinity.leading, // <-- leading Checkbox ); final rtCheckBox = CheckboxListTile( title: Text("Real-time Tracking"), value: _tracking, onChanged: (newValue) => setState(() => _tracking = newValue), controlAffinity: ListTileControlAffinity.leading, // <-- leading Checkbox ); final descriptionText = Text( "Description:", style: TextStyle(fontSize: 12.0), ); final description = TextFormField( decoration: InputDecoration( hintText: 'Enter an activity description', ), ); final scheduledFor = Text( "Scheduled for:", style: TextStyle(fontSize: 12.0), ); final dropdown = DropdownButton<String>( value: _schedule, items: <String>['Now (Default)', 'B', 'C', 'D'].map((String value) { return DropdownMenuItem<String>( value: value, child: Text(value), ); }).toList(), hint: Text("Now (Default)"), onChanged: (newValue) { setState(() { _schedule = newValue; }); }, ); final readButton = Container( padding: EdgeInsets.symmetric(vertical: 16.0), width: 170, //MediaQuery.of(context).size.width, child: RaisedButton( onPressed: () => {}, color: Colors.lightBlue, child: Text("Start", style: TextStyle(color: Colors.white, fontSize: 20)), )); final bottomContent = Container( width: MediaQuery.of(context).size.width, padding: EdgeInsets.all(40.0), child: Center( child: Column( children: <Widget>[bottomContentText, mappedCheckbox, rtCheckBox, descriptionText, description, Text("n"), scheduledFor, dropdown, readButton], ), ), ); return Scaffold( body: Column( children: <Widget>[topContent, bottomContent], ), ); }}
