Flutter/Dart - Open a view after a delay

Question

I'm trying to find a solution to open a view after a delay in a loading view. I have a View, in which there is a button and when I press it, the onPressed() method triggers a Navigator.of(Context).pushNamed("/loading"). which opens the loading view. In the loading view I have then a function to make a delay of 1.5 sec and then open the home view, this is the code:

Future delay() async{ await new Future.delayed(new Duration(milliseconds: 1500), () {    Navigator.of(context).pushNamed("/home");  } 

However, when the delay starts, after 1.5 sec, it opens the Home view, but with this exception:

I/flutter ( 5226): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════ I/flutter ( 5226): The following assertion was thrown building IconTheme(color: Color(0xff000000)): I/flutter ( 5226): Multiple widgets used the same GlobalKey. I/flutter ( 5226): The key [LabeledGlobalKey<ScaffoldState>#a0051] was used by multiple widgets. The parents of those I/flutter ( 5226): widgets were different widgets that both had the following description: I/flutter ( 5226):   IconTheme(color: Color(0xff000000)) I/flutter ( 5226): A GlobalKey can only be specified on one widget at a time in the widget tree. I/flutter ( 5226): When the exception was thrown, this was the stack: I/flutter ( 5226): #0      GlobalKey._debugReserveFor.<anonymous closure> (package:flutter/src/widgets/framework.dart:172:9) I/flutter ( 5226): #1      GlobalKey._debugReserveFor (package:flutter/src/widgets/framework.dart:182:6) I/flutter ( 5226): #2      Element.updateChild.<anonymous closure> (package:flutter/src/widgets/framework.dart:2649:13) I/flutter ( 5226): #3      Element.updateChild (package:flutter/src/widgets/framework.dart:2652:6) I/flutter ( 5226): #4      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #5      Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #6      ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #7      ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #8      Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #9      Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #10     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #11     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #12     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #13     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #14     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #15     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #16     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #17     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #18     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #19     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #20     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #21     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #22     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #23     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #24     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #25     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #26     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #27     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #28     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #29     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #30     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #31     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #32     ParentDataElement.mount (package:flutter/src/widgets/framework.dart:3893:16) I/flutter ( 5226): #33     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #34     MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4693:32) I/flutter ( 5226): #35     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #36     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #37     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #38     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #39     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #40     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #41     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #42     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #43     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #44     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #45     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #46     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #47     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #48     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #49     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #50     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #51     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #52     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #53     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #54     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #55     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #56     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #57     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #58     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #59     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #60     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #61     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #62     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #63     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #64     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #65     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #66     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #67     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #68     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #69     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #70     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #71     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #72     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #73     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #74     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #75     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #76     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #77     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #78     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #79     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #80     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #81     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #82     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #83     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #84     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #85     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #86     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #87     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #88     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #89     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #90     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #91     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #92     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #93     Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #94     Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #95     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #96     Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #97     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #98     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #99     ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #100    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #101    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #102    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #103    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #104    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #105    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #106    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #107    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #108    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #109    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #110    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #111    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #112    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #113    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #114    SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #115    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #116    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #117    SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #118    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #119    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #120    SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #121    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #122    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #123    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #124    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #125    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #126    StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #127    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #128    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #129    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #130    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #131    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #132    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #133    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #134    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #135    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #136    SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #137    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #138    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #139    SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #140    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #141    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #142    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #143    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #144    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #145    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) E/flutter ( 5226): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception: E/flutter ( 5226): NoSuchMethodError: The method 'ancestorStateOfType' was called on null. E/flutter ( 5226): Receiver: null E/flutter ( 5226): Tried calling: ancestorStateOfType(Instance of 'TypeMatcher<NavigatorState>') E/flutter ( 5226): #0      Object.noSuchMethod (dart:core-patch/dart:core/object_patch.dart:46) E/flutter ( 5226): #1      Navigator.of (package:flutter/src/widgets/navigator.dart:722:19) E/flutter ( 5226): #2      Navigator.pushReplacementNamed (package:flutter/src/widgets/navigator.dart:666:22) E/flutter ( 5226): #3      switcher (package:ticketing/router.dart:53:13) E/flutter ( 5226): #4      _LoadingViewState.switchView (/data/user/0/com.tiziano.flutterapp.flutterapp2/cache/ticketing_remasteredAHSWSC/ticketing_remastered/lib/view/loadingview/LoadingView.dart:79:3) E/flutter ( 5226): #5      _LoadingViewState.delay.<anonymous closure> (/data/user/0/com.tiziano.flutterapp.flutterapp2/cache/ticketing_remasteredAHSWSC/ticketing_remastered/lib/view/loadingview/LoadingView.dart:74:70) E/flutter ( 5226): #6      new Future.delayed.<anonymous closure> (dart:async/future.dart:310) E/flutter ( 5226): #7      Timer._createTimer.<anonymous closure> (dart:async-patch/dart:async/timer_patch.dart:21) E/flutter ( 5226): #8      _Timer._runTimers (dart:isolate-patch/dart:isolate/timer_impl.dart:367) E/flutter ( 5226): #9      _Timer._handleMessage (dart:isolate-patch/dart:isolate/timer_impl.dart:401) E/flutter ( 5226): #10     _RawReceivePortImpl._handleMessage (dart:isolate-patch/dart:isolate/isolate_patch.dart:164) I/flutter ( 5226): #146    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #147    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #148    SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4588:14) I/flutter ( 5226): #149    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #150    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #151    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #152    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #153    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #154    StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #155    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #156    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #157    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #158    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #159    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #160    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #161    StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #162    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #163    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #164    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #165    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #166    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #167    ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3582:5) I/flutter ( 5226): #168    StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3718:22) I/flutter ( 5226): #169    ComponentElement.mount (package:flutter/src/widgets/framework.dart:3577:5) I/flutter ( 5226): #170    Element.inflateWidget (package:flutter/src/widgets/framework.dart:2875:14) I/flutter ( 5226): #171    Element.updateChild (package:flutter/src/widgets/framework.dart:2678:12) I/flutter ( 5226): #172    RenderObjectElement.updateChildren (package:flutter/src/widgets/framework.dart:4375:32) I/flutter ( 5226): #173    MultiChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4703:17) I/flutter ( 5226): #174    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #175    _TheatreElement.update (package:flutter/src/widgets/overlay.dart:507:16) I/flutter ( 5226): #176    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #177    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #178    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #179    StatefulElement.update (package:flutter/src/widgets/framework.dart:3737:5) I/flutter ( 5226): #180    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #181    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #182    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #183    ProxyElement.update (package:flutter/src/widgets/framework.dart:3847:5) I/flutter ( 5226): #184    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #185    SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4595:14) I/flutter ( 5226): #186    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #187    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #188    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #189    StatefulElement.update (package:flutter/src/widgets/framework.dart:3737:5) I/flutter ( 5226): #190    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #191    SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4595:14) I/flutter ( 5226): #192    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #193    SingleChildRenderObjectElement.update (package:flutter/src/widgets/framework.dart:4595:14) I/flutter ( 5226): #194    Element.updateChild (package:flutter/src/widgets/framework.dart:2667:15) I/flutter ( 5226): #195    ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3613:16) I/flutter ( 5226): #196    Element.rebuild (package:flutter/src/widgets/framework.dart:3463:5) I/flutter ( 5226): #197    BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2210:33) I/flutter ( 5226): #198    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:621:20) I/flutter ( 5226): #199    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5) I/flutter ( 5226): #200    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15) I/flutter ( 5226): #201    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9) I/flutter ( 5226): #202    BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:842:5) I/flutter ( 5226): #203    _invoke (file:///b/build/slave/Linux_Engine/build/src/flutter/lib/ui/hooks.dart:120) I/flutter ( 5226): #204    _drawFrame (file:///b/build/slave/Linux_Engine/build/src/flutter/lib/ui/hooks.dart:109) I/flutter ( 5226): ════════════════════════════════════════════════════════════════════════════════════════════════════ I/flutter ( 5226): Another exception was thrown: Multiple widgets used the same GlobalKey. 

By the way, in the Home View there aren't any black icons. (IconTheme(color: Color(0xff000000)) Can someone help?

Answer 1

To open a view after some delay you can use Future.delayed:

Future.delayed(const Duration(milliseconds: 500), () {   setState(() {     // Here you can write your code for open new view   }); }); 

Hope it will help you out.

Answer 2

You can do it in 2 ways:

• Using Timer class.

  import 'dart:async';  // Go to Page2 after 5s. Timer(Duration(seconds: 5), () {   Navigator.push(context, MaterialPageRoute(builder: (_) => Screen2())); }); 

• Using Future.delayed class:

  // Go to Page2 after 5s. Future.delayed(Duration(seconds: 5), () {   Navigator.push(context, MaterialPageRoute(builder: (_) => Screen2())); }); 

The benefit of using Timer over Future is its ability to cancel.