添加Drawer 抽屜效果

 Scaffold.of(context).openDrawer();

報錯
Another exception was thrown: Scaffold.of() called with a context that does not contain a Scaffold.

1.聲明

final GlobalKey<ScaffoldState> _scaffoldKey =  GlobalKey();

2. 在Scaffold添加key

 @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: _scaffoldKey,
)}

3.用_scaffoldKey 調用Drawer

_scaffoldKey.currentState!.openEndDrawer();