Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

AddDynamic is permanent!

Hello guys,

I'm using UE 4.18. I find myself in this situation, in a constructor I have:

 CapsuleComponent->OnComponentBeginOverlap.AddDynamic(this, &ABaseCharacter::OnCoverVolumeBeginOverlap)

This is the ONLY place where the function OnCoverVolumeBeginOverlap is added to the delegate OnComponentBeginOverlap. It all works fine until I decided I don't need this binding. So what did I do? I removed this code from my constructor. Guess what? This thing doesn't go away. The function OnCoverVolumeBeginOverlap keeps getting called. I cleaned my solution, rebuild it several times, deleted the Binaries, Intermediate folders and it still persists. What is going on? This is driving me crazy. I'm absolutely sure this is the only place that this binding is happening. I tried calling OnComponentBeginOverlap.Clear(), still doesn't help. Anyone experienced such madness?

Best regards.

Product Version: UE 4.18
more ▼

asked Jan 31 '18 at 01:33 PM in C++ Programming

avatar image

89 5 17 21

(comments are locked)
10|2000 characters needed characters left

2 answers: sort voted first

Posting here for completion's sake:

I suspect what is happening is that a blueprint subclass of this class is causing the issue. Some UE4 delegates can be serialized (saved), and when you created the blueprint, the constructor created that delegate binding and serialized it to the saved blueprint asset.

If you change the constructor of a class in C++, there's no guarantee that those changes will propagate to existing blueprint assets you have created - so you will have to delete and re-create the blueprint from scratch. There isn't an easy solution to this problem in general, unfortunately.

In this particular case, you might be able to add a 'Clear' method to the constructor then open and re-save the blueprint asset.

Hope this helps!

more ▼

answered Jan 31 '18 at 02:15 PM

avatar image

775 53 83 131

avatar image kbrizov Jan 31 '18 at 02:27 PM

Hello TheJamsh, I will give a try ASAP. That's a very good guess. Will let you know how it goes.

avatar image kbrizov Jan 31 '18 at 03:56 PM

For future readers, indeed the only way to fix it was to recreate the blueprint. I tried using OnComponentBeginOverlap.RemoveAll(), OnComponentBeginOverlap.RemoveDynamic(), OnComponentBeginOverlap.Clear() in the constructor in question and nothing helped.

(comments are locked)
10|2000 characters needed characters left

Ehi dude, I know that some time has passed and you may have found a better solution, in any case I have found an easy and quick way to fix this problem: my the trick is to remove the bindings to the delegate in the BP "Event Graph", for example after the Beginplay or some other default or custom event. For example I have a custom userwidget which I've implemented in C++, delegates included. When I create the derived BP for design its widgets, I go to the Event Graph and from the "Pre-Construct" node I remove all the bindings to my delegate. This works fine and you don't need to delete and recreate the BP every time !

Cheers! alt text

ueforumanswer.png (39.0 kB)
more ▼

answered Jan 08 '19 at 09:08 AM

avatar image


avatar image kbrizov Jan 08 '19 at 01:58 PM

Hello evethir!

Thanks for taking your time giving a tip. Your solution is reasonable! Good job coming up with it. I remember this problem. I was really frustrated with it but I can see why it ends behaving like that. It does make sense to act the way it does. I came up with a workflow that eliminates this kind of issues. I bind my delegates in events like BeginPlay or something else and I avoid binding in the constructors since the editor uses them as well and things can go wrong. So far I can't see any disadvantages to this "new" workflow.

Happy New Year!

(comments are locked)
10|2000 characters needed characters left
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question