Throw an exception when onTabChanged is null

[heafox]

217 widget.onTabChanged!(_tabController?.index);

[alihaider78222]

Hi @heafox,

Could you please share all the logs (if possible an example) causing this exception, this will help us to quickly figure out the root cause and then resolve the issue as soon as possible!

[Pocus76]

Hi, I'm actually having the same problem with version 1.0.8,
File dynamic_tabbar.dart, line 242, widget.onTabChanged!(_tabController?.index); throws _TypeError (Null check operator used on a null value)
Here's the stacktrace :
_DynamicTabBarWidgetState.getTabController.. (----\Pub\Cache\hosted\pub.dev\dynamic_tabbar-1.0.8\lib\dynamic_tabbar.dart:242)
State.setState (---\flutter\flutter\packages\flutter\lib\src\widgets\framework.dart:1203)
_DynamicTabBarWidgetState.getTabController. (---\AppData\Local\Pub\Cache\hosted\pub.dev\dynamic_tabbar-1.0.8\lib\dynamic_tabbar.dart:239)
ChangeNotifier.notifyListeners (---\flutter\flutter\packages\flutter\lib\src\foundation\change_notifier.dart:437)
TabController._changeIndex (---\flutter\flutter\packages\flutter\lib\src\material\tab_controller.dart:208)
TabController.animateTo (----\flutter\flutter\packages\flutter\lib\src\material\tab_controller.dart:261)
_TabBarState._handleTap (---\flutter\flutter\packages\flutter\lib\src\material\tabs.dart:1596)
_TabBarState.build. (----\flutter\flutter\packages\flutter\lib\src\material\tabs.dart:1753)
_InkResponseState.handleTap (---\flutter\flutter\packages\flutter\lib\src\material\ink_well.dart:1170)
GestureRecognizer.invokeCallback (---\flutter\flutter\packages\flutter\lib\src\gestures\recognizer.dart:351)
TapGestureRecognizer.handleTapUp (---\flutter\flutter\packages\flutter\lib\src\gestures\tap.dart:656)
BaseTapGestureRecognizer._checkUp (---\flutter\flutter\packages\flutter\lib\src\gestures\tap.dart:313)
BaseTapGestureRecognizer.acceptGesture (---\flutter\flutter\packages\flutter\lib\src\gestures\tap.dart:283)
GestureArenaManager.sweep (---\flutter\flutter\packages\flutter\lib\src\gestures\arena.dart:169)
GestureBinding.handleEvent (---\flutter\flutter\packages\flutter\lib\src\gestures\binding.dart:505)
GestureBinding.dispatchEvent (---\flutter\flutter\packages\flutter\lib\src\gestures\binding.dart:481)
RendererBinding.dispatchEvent (---\flutter\flutter\packages\flutter\lib\src\rendering\binding.dart:450)
GestureBinding._handlePointerEventImmediately (---\flutter\flutter\packages\flutter\lib\src\gestures\binding.dart:426)
GestureBinding.handlePointerEvent (---\flutter\flutter\packages\flutter\lib\src\gestures\binding.dart:389)
GestureBinding._flushPointerEventQueue (---\flutter\flutter\packages\flutter\lib\src\gestures\binding.dart:336)
GestureBinding._handlePointerDataPacket (---\flutter\flutter\packages\flutter\lib\src\gestures\binding.dart:305)
_invoke1 (---\flutter\flutter\bin\cache\pkg\sky_engine\lib\ui\hooks.dart:328)
PlatformDispatcher._dispatchPointerDataPacket (---\flutter\flutter\bin\cache\pkg\sky_engine\lib\ui\platform_dispatcher.dart:442)
_dispatchPointerDataPacket (---\flutter\flutter\bin\cache\pkg\sky_engine\lib\ui\hooks.dart:262)

Thanks for your help

[JohnGalt1717]

I too am getting this and I can't find a way to set a tab controller.