I don't know why this code make crash

Development Programming & Scripting
1

void ALopolProjectPlayerController::TotalControlFunction(const ETouchIndex::Type FingerIndex, const FVector Location)
{

GetHitResultUnderFinger(ETouchIndex::Touch1, ECC_Camera, true, TouchedResult);

ALopolProjectCharacter* TouchedActor = Cast<ALopolProjectCharacter>(TouchedResult.Actor);

if (TouchedActor->IsEnemy() == false)
{
	ALopolPlayerCharacter* TouchedPlayerCharacter = Cast<ALopolPlayerCharacter>(TouchedActor);

	if (TouchedPlayerCharacter)
	{

		TouchedPlayerCharacter->SetIsCharacterSelected(true);
		bCheckCharacterSelected = TouchedPlayerCharacter->IsCharacterSelected();

		TouchCheckDisplay = UKismetStringLibrary::Conv_BoolToString(bCheckCharacterSelected);
		GEngine->AddOnScreenDebugMessage(-1, 1.f, FColor::Red, TouchCheckDisplay);

		
	}

}

It always makes the crash wherever I click, except clicking the ‘LopolPlayerCharacter’. I don’t know why this occur.
Where is incorrect?

Below is Crash Information.

Access violation - code c0000005 (first/second chance not available)

UE4Editor_LopolProject_7090!ALopolProjectCharacter::IsEnemy() [f:\lopolproject\source\lopolproject\lopolprojectcharacter.cpp:162]
UE4Editor_LopolProject_7090!ALopolProjectPlayerController::TotalControlFunction() [f:\lopolproject\source\lopolproject\lopolprojectplayercontroller.cpp:133]
UE4Editor_LopolProject_7090!TBaseUObjectMethodDelegateInstance<0,ALopolProjectPlayerController,TTypeWrapper __cdecl(enum ETouchIndex::Type,FVector)>::Execute() [c:\program files\epic games\ue_4.21\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:618]
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

2

Edit line 5 from this

if (TouchedActor->IsEnemy() == false)

to this

if (TouchedActor && TouchedActor->IsEnemy() == false)

It should prevent the crash as it will skip everything if the Cast fails.

3

I would try the same thing. It sounds to me like that the pointer to “TouchedActor” returns NULL, which then results in a crash (unreal does not like NULL pointers). One way is to circumnavigate this problem by doing what is mentioned above my response. I would also try to figure out why the cast fails in the first place.

4

Very thank you for some informations about it… It would be very helpful to me. Thank you.