How to hide drawer in flutter after changing Scaffold.body value

Are you using exactly Navigator.of(context).pop()? I cannot reproduce your problem, can you post a minimal example to reproduce it?

The following code works as expected: the settings button pops away the drawer, while the other don't.

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  String text = "Initial Text";

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        drawer: new Drawer(
          child: new ListView(
            children: <Widget>[
              new Container(child: new DrawerHeader(child: new Container())),
              new Container (
                child: new Column(
                    children: <Widget>[
                      new ListTile(leading: new Icon(Icons.info),
                          onTap:(){
                            setState((){
                              text = "info pressed";
                            });
                          }
                      ),
                      new ListTile(leading: new Icon(Icons.save),
                          onTap:(){
                            setState((){
                              text = "save pressed";
                            });
                          }
                      ),
                      new ListTile(leading: new Icon(Icons.settings),
                          onTap:(){
                            setState((){
                              text = "settings pressed";
                            });
                            Navigator.of(context).pop();
                          }
                      ),

                    ]
                ),
              )
            ],
          ),
        ),
        appBar: new AppBar(title: new Text("Test Page"),),
        body: new Center(child: new Text((text)),
        ));
  }
}

create scaffoldKey

close drawer

 _scaffoldKey.currentState.openEndDrawer(),

open drawer

scaffoldKey.currentState.openDrawer(),

Example

     InkWell(
        onTap: ()=> widget.scaffoldKey.currentState.openDrawer(),
        child: Icon(
          Icons.menu,
          size: 38,
          color: Color(0xFFFFFFFF),
        ),
      ),