当我点击FloatingActionButton. 你能帮我吗？当我按下物理设备上的按钮时，我的程序停止，我必须从调试工具中恢复它。这是我的代码：
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
final mediaQuery = MediaQuery.of(context);
final appbar = appbarBuilder();
return Scaffold(
appBar: appbar,
body: body,
floatingActionButton: FloatingActionButton(
backgroundColor: Colors.blue,
onPressed: () async {
const url = 'https://www.google.gr/?hl=el';
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
}
},
child: Image.asset(
'assets/instagram.png',
color: Colors.black,
),
),
);
}
}