OnDrop is not called if something else takes the OnPointerClick event?

I've found that OnBeginDrag, OnDrag, and OnEndDrag are all called like normal, in this situation, but OnDrop is ignored.

So far, I've only tested it with the OnPointerClick event in a separate monobehaviour on the same GameObject (which had an Image component attached to it, to catch the events).

This seems like a bug, since I wouldn't expect two, different events to override each other. If anything, this would only make sense if both events relied on the same basal event (like OnRelease), but even then, it's a bit perplexing why they override each other, since the criteria for calling them don't overlap. If OnPointerClick succeeds, it means you didn't drag the pointer far enough to start a drag event. If OnDrop succeeds, it means you moved your pointer far enough to start a drag event, which is too far for OnPointerClick to succeed from.

 

Code (CSharp):

1. if (!event.used)
2. {
3.     event.Use();
4.    ...
5. }

 

What does that have to do with anything? I'm not trying to make it so that the event gets used up... I'm suggesting that the event should not be used up, if the failed event tests first (which I really have little to no control over).

 

Did you find a solution for this? I've the same problem right now. Thanks.

 

It's been a bit since I did my drag'n'drop inventory, but if I recall... something that implemented the Drag interfaces could not implement the Drop interfaces. They simply could not coexist on the same monobehavior.

It sort of makes sense. OnEndDrag is basically OnDrop in theory. So separating them in my mind made sense. You drag an object, and the container you drop it into uses drop to determine if something is being dropped into it.

 

Right, I also got it working that way. I followed this video and extended my logic:

The canvasGroup.blocksRaycasts is important to know, so that the dragged object doesn't get the hits (raycast). Then another object with an OnDrop handler can be hit.

Code (JavaScript):

1. function OnBeginDrag(eventData : PointerEventData) {
2.     // some code
3.     canvasGroup.blocksRaycasts = false;
4. }
5.  
6. function OnEndDrag(eventData : PointerEventData) {
7.     // some code
8.     canvasGroup.blocksRaycasts = true
9. }

 

I got it working by disabling EventTrigger when it suited me, and then enabling it afterwards.

 

haha like anyone stumbles over the same issues. Just make sure you disable Raycast for those Elements that shouldn't react to onDrop. In my case it was the Image of the Panel that had Raycast enabled.

Now it's working like a charm.

Edit:

You may also consider using Canvas Groups, which helps to block raycast out for certain components.

 

Thank you.
This seems to be working for me.

 

I can't hear this video it sounds like he is eating my ear I am having the same issue and my problem is that the OnDrop() function just doesn't work it would be lovely if someone were to take a look everything is in this thread
https://forum.unity.com/threads/grid-map-doesnt-work.1574305/