I found that FlowChartX isn't properly destroyed when I destroy the form where it is instanteated, and my program ends in a crash, sooner or later.

After a full week trying to find out what could be wrong, I found that it only happens after initiating a Drag&Drop operation with FlowChartX. A simple DragOver, without dropping, is enough to cause troubles.

In my environment I have the need to use *VB events during DragDrop operations.

I'm able to query DataObject.GetFormat and proceed with GetData method, and everything seems to work fine. But the "Garbage Collector" is unable to clean up things after closing FC, so it seems that some reference to IVBDataObject is left behind. I even tryed to call RevokeDragDrop after each operation, but the result is the same.

Is there anything else I can try?

Thanks

fcxWindow is the form where I put FlowChartX.

When I don't need the fcxWindow anymore I call fcx:EndWindow(). This way the dynamic memory and resources used by fcxWindow are marked as free and usable again. If the program needs to allocate some more dynamic memory, it uses the so called "Garbage Collector" to clear the memory marked as free, so it can be used by some other process.

Usualy the "Garbage Collector" is only called in low memory situations, like after a long run with several operations that require dynamic memory allocation, and that's why I didn't noticed it before.

I don't keep external references to fcx objects outside fcxWindow, and I don't create objects in event methods. If I don't drag anything over fcxWindow, EndWindow works fine and the memory is freed. However if I drag whatever over it the program crashes with an error in FlowChartPro.dll when calling fcxWindow:EndWindow(), even if I don't use the drag/drop events.

So, I'm sure it's something related with DragDrop, but I can't figure out what.

The (empty) method I use to catch the DragOver event:

method DiagramDragOverDocVB(DataObj, DocX, DocY, KeyState, Effect) class Database
return nil

The problem starts as soon as I define this method and drag something over fcxWindow. As you can see I don't do nothing, just return from it. I can use Drag&Drop with any other window/control.

However, if I make DragDropMode := drProgrControl instead of drProgrControlVB and strip out the "VB" from the method everything works fine again.