颤动 – 在appbar处更改抽屉的菜单图标

import "package:Flutter/material.dart";

class Test extends StatefulWidget {
  @override
  _TestState createState() => new _TestState();
}

class _TestState extends State<Test> {
  final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      key: _scaffoldKey,drawer: new Drawer(),appBar: new AppBar(
        leading: new IconButton(icon: new Icon(Icons.setTings),onPressed: () => _scaffoldKey.currentState.openDrawer()),),);
  }
}