做了一些打印, 看到登录成功后 page 是null
flutter: routeStatus----: RouteStatus.home pages----: [MaterialPage(“null”, [<922893423>], null)]
flutter: index–: -1
flutter: tempPages：[] page: null
登录成功跳转首页报错

The following _TypeError was thrown building Builder(dirty):
type 'Null' is not a subtype of type 'MaterialPage<dynamic>'

The relevant error-causing widget was: 
  Router<CrmRoutePath> Router:file:///Users/luodan/yl_work/yl_platform_web/web-2.0.0/yl_crm_app/lib/main.dart:35:17
When the exception was thrown, this was the stack: 
#0      CrmRouteDelegate.build (package:yl_crm_app/main.dart:104:32)
#1      Builder.build (package:flutter/src/widgets/basic.dart:7371:48)
#2      StatelessElement.build (package:flutter/src/widgets/framework.dart:4876:49)
#3      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4806:15)
#4      Element.rebuild (package:flutter/src/widgets/framework.dart:4529:5)
#5      StatelessElement.update (package:flutter/src/widgets/framework.dart:4883:5)
#6      Element.updateChild (package:flutter/src/widgets/framework.dart:3530:15)
#7      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4832:16)
#8      Element.rebuild (package:flutter/src/widgets/framework.dart:4529:5)
#9      ProxyElement.update (package:flutter/src/widgets/framework.dart:5154:5)
#10     Element.updateChild (package:flutter/src/widgets/framework.dart:3530:15)
#11     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4832:16)
#12     Element.rebuild (package:flutter/src/widgets/framework.dart:4529:5)
#13     ProxyElement.update (package:flutter/src/widgets/framework.dart:5154:5)
#14     Element.updateChild (package:flutter/src/widgets/framework.dart:3530:15)
#15     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4832:16)
#16     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4977:11)
#17     Element.rebuild (package:flutter/src/widgets/framework.dart:4529:5)
#18     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2659:19)
#19     WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:891:21)
#20     RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:370:5)
#21     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1146:15)
#22     SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1083:9)
#23     SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:997:5)
#27     _invoke (dart:ui/hooks.dart:151:10)
#28     PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:308:5)
#29     _drawFrame (dart:ui/hooks.dart:115:31)
(elided 3 frames from dart:async)