showDialog(context: context,builder: (context) {String label = 'test';//StatefulBuilderreturn StatefulBuilder(//在這里為了區分，在構建builder的時候將setState方法命名為了setDialogState。builder: (context, setDialogState) {print('label = $label');return GestureDetector(child: Text(label),onTap: () {label = 'test8';print('onTap:label = $label');// 注意不是調用老頁面的setState，而是要調用builder中的setDialogState。setDialogState(() {});  },);},);});

bottomsheet

bool btnState=false;
showModalBottomSheet(context:context, builder:(BuildContext context){return StatefulBuilder(//在這里為了區分，在構建builder的時候將setState方法命名為了setBottomSheetState。builder:(context1, setBottomSheetState) {return Container(child:OutlineButton(onPressed: (){// 注意不是調用老頁面的setState，而是要調用builder中的setBottomSheetStatesetBottomSheetState(() {btnState=!btnState;});},child:Stack(children: <Widget>[Opacity(opacity: btnState ? 0.0 : 1.0,child: Text("aa"),),Opacity(opacity: btnState ? 1.0 : 0.0,child: Text("bb"),),],),),),}）}
)