1、Center介绍
Center将子控件放在其内部中心，里面只能放一个child，但是child里面可以放Container
Center继承勒Align，然后Align默认是center.
2、测试代码
测试1、
@override Widget build(BuildContext context) { return MaterialApp( title: 'open url', home: Scaffold( appBar: AppBar( // Here we take the value from the MyHomePage object that was created by // the App.build method, and use it to set our appbar title. title: Text('hello flutter'), ), body: Center( child: Text("chenyu"), ), ), ); } }
测试2、
@override Widget build(BuildContext context) { return MaterialApp( title: 'open url', home: Scaffold( appBar: AppBar( // Here we take the value from the MyHomePage object that was created by // the App.build method, and use it to set our appbar title. title: Text('hello flutter'), ), body: Center( child: Container( color: Colors.blue, width: 200, height: 200, ), ), ), ); } }