leading 属性可以设置左边的按钮。

class Home extends StatelessWidget {
  @override
    Widget build(BuildContext context) {
      return Scaffold(
        backgroundColor: Colors.grey[100],
            appBar: AppBar(
              title: Text('Muzico'),
              elevation: 0.0,
              leading: IconButton(
                icon: Icon(Icons.menu),
                tooltip: 'Navigation',
                onPressed: () => debugPrint('Navigation button is pressed.'),
              ),
            ),
            body: null,
          );
    }
}

actions 可以设置右边的按钮，可以设置很多个

class Home extends StatelessWidget {
  @override
    Widget build(BuildContext context) {
      return Scaffold(
        backgroundColor: Colors.grey[100],
            appBar: AppBar(
              title: Text('Muzico'),
              elevation: 0.0,
              leading: IconButton(
                icon: Icon(Icons.menu),
                tooltip: 'Navigation',
                onPressed: () => debugPrint('Navigation button is pressed.'),
              ),
              actions: <Widget>[
                 IconButton(
                   icon: Icon(Icons.search),
                   tooltip: 'Search',
                   onPressed: () => debugPrint('Search button is pressed.'),
                 ),
              ],
            ),
            body: null,
          );
    }
}

actions 设置多个的时候，中间的title的位置会发生改变。

class Home extends StatelessWidget {
  @override
    Widget build(BuildContext context) {
      return Scaffold(
        backgroundColor: Colors.grey[100],
            appBar: AppBar(
              title: Text('Muzico'),
              elevation: 0.0,
              leading: IconButton(
                icon: Icon(Icons.menu),
                tooltip: 'Navigation',
                onPressed: () => debugPrint('Navigation button is pressed.'),
              ),
              actions: <Widget>[
                 IconButton(
                   icon: Icon(Icons.search),
                   tooltip: 'Search',
                   onPressed: () => debugPrint('Search button is pressed.'),
                 ),
                 IconButton(
                   icon: Icon(Icons.more),
                   tooltip: 'More',
                   onPressed: () => debugPrint('More button is pressed.'),
                 ),
              ],
            ),
            body: null,
          );
    }
}

actions 设置很多个的时候，会导致 title 消失；而多到超越位置的时候，位置会过了左边的按钮的位置，看起来不能太多个比较好。