19.8.12 记录Scaffold（脚手架）的常见属性及使用

Scaffold(
      appBar: AppBar(
        title: Text(‘课程‘),
      ),
      body: Text(‘课程页面‘),
      bottomNavigationBar: BottomAppBar(
        child: Container(
          height: 50,
          child: Text(‘333‘),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          print(‘点击触发事件‘);
        },
        child: Icon(Icons.print),
      ),
      floatingActionButtonLocation: FloatingActionButtonLocation.endFloat,//设置浮动按钮位置
    )