添加Drawer 抽屉效果

 Scaffold.of(context).openDrawer();

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

1.声明

final GlobalKey<ScaffoldState> _scaffoldKey =  GlobalKey();

2. 在Scaffold添加key

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

3.用_scaffoldKey 调用Drawer

_scaffoldKey.currentState!.openEndDrawer();