代码:classMyAppextendsStatelessWidget{@overrideWidgetbuild(BuildContextcontext){returnMaterialApp(home:Scaffold(appBar:AppBar(leading:IconButton(icon:Icon(Icons.help),onPressed:(){//howcanIcallmethodAfromhere?},),),body:HomePage(),),);}}classHomePageextendsStatefulWidget{@override_HomePageStatecre

代码:classMyAppextendsStatelessWidget{@overrideWidgetbuild(BuildContextcontext){returnMaterialApp(home:Scaffold(appBar:AppBar(leading:IconButton(icon:Icon(Icons.help),onPressed:(){//howcanIcallmethodAfromhere?},),),body:HomePage(),),);}}classHomePageextendsStatefulWidget{@override_HomePageStatecre