即使在为 Container GridView 指定高度之后,我的代码仍在生成方形小部件。
class MyHomePage extends StatefulWidget { MyHomePage({Key key, this.title}) : super(key: key); final String title; @override _MyHomePageState createState() => new _MyHomePageState(); } class _MyHomePageState extends State<MyHomePage> { List<String> widgetList = ['A', 'B', 'C']; @override Widget build(BuildContext context) { return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new Container( child: new GridView.count( crossAxisCount: 2, controller: new ScrollController(keepScrollOffset: false), shrinkWrap: true, scrollDirection: Axis.vertical, children: widgetList.map((String value) { return new Container( height: 250.0, color: Colors.green, margin: new EdgeInsets.all(1.0), child: new Center( child: new Text( value, style: new TextStyle(fontSize: 50.0,color: Colors.white), ), ), ); }).toList(), ), ), ); } }
上面代码的输出如左图所示。如何获得带有自定义高度小部件的 GridView,如右图所示?
关键是childAspectRatio. 此值用于确定 中的布局GridView。为了获得所需的方面,您必须将其设置为 ( itemWidth/ itemHeight)。解决方案是这样的:
childAspectRatio
GridView
itemWidth
itemHeight
class MyHomePage extends StatefulWidget { MyHomePage({Key key, this.title}) : super(key: key); final String title; @override _MyHomePageState createState() => new _MyHomePageState(); } class _MyHomePageState extends State<MyHomePage> { List<String> widgetList = ['A', 'B', 'C']; @override Widget build(BuildContext context) { var size = MediaQuery.of(context).size; /*24 is for notification bar on Android*/ final double itemHeight = (size.height - kToolbarHeight - 24) / 2; final double itemWidth = size.width / 2; return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new Container( child: new GridView.count( crossAxisCount: 2, childAspectRatio: (itemWidth / itemHeight), controller: new ScrollController(keepScrollOffset: false), shrinkWrap: true, scrollDirection: Axis.vertical, children: widgetList.map((String value) { return new Container( color: Colors.green, margin: new EdgeInsets.all(1.0), child: new Center( child: new Text( value, style: new TextStyle( fontSize: 50.0, color: Colors.white, ), ), ), ); }).toList(), ), ), ); } }