If you forget to inject controller in Getx flutter, then you will get below error
Performing hot restart...
Syncing files to device iPhone 13 mini...
Restarted application in 431ms.
[GETX] Instance "GetMaterialController" has been created
[GETX] Instance "GetMaterialController" has been initialized
======== Exception caught by widgets library =======================================================
The following _CastError was thrown building Container:
Null check operator used on a null value
The relevant error-causing widget was:
Container Container:file:///Users/ahmeddastagir/Documents/Dbestech_github/provider_test/lib/home_page.dart:24:24
When the exception was thrown, this was the stack:
#0 GetBuilderState.initState (package:get/get_state_manager/src/simple/get_state.dart:134:40)
#1 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4893:57)
#2 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4729:5)
#3 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3790:14)
#4 MultiChildRenderObjectElement.inflateWidget (package:flutter/src/widgets/framework.dart:6422:36)
#5 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6433:32)
... Normal element mounting (13 frames)
#18 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3790:14)
#19 MultiChildRenderObjectElement.inflateWidget (package:flutter/src/widgets/framework.dart:6422:36)
#20 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6433:32)
... Normal element mounting (28 frames)
#48 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3790:14)
#49 MultiChildRenderObjectElement.inflateWidget (package:flutter/src/widgets/framework.dart:6422:36)
#50 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6433:32)
... Normal element mounting (114 frames)
#164 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3790:14)
#165 MultiChildRenderObjectElement.inflateWidget (package:flutter/src/widgets/framework.dart:6422:36)
#166 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6433:32)
... Normal element mounting (175 frames)
#341 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3790:14)
#342 MultiChildRenderObjectElement.inflateWidget (package:flutter/src/widgets/framework.dart:6422:36)
#343 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6433:32)
... Normal element mounting (388 frames)
#731 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3790:14)
#732 Element.updateChild (package:flutter/src/widgets/framework.dart:3540:18)
#733 RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets/binding.dart:1198:16)
#734 RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:1167:5)
#735 RenderObjectToWidgetAdapter.attachToRenderTree.<anonymous closure> (package:flutter/src/widgets/binding.dart:1112:18)
#736 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2600:19)
#737 RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:1111:13)
#738 WidgetsBinding.attachRootWidget (package:flutter/src/widgets/binding.dart:944:7)
#739 WidgetsBinding.scheduleAttachRootWidget.<anonymous closure> (package:flutter/src/widgets/binding.dart:924:7)
(elided 11 frames from class _RawReceivePortImpl, class _Timer, dart:async, and dart:async-patch)So all you need to do is to inject the controller (dependency injection)before you run your MaterialApp()
In the above photo you can see that, I am using Get.lazyPut() to inject the DataClass controller.