TreeView expand/collaps icons issue


I have an unexpected behavior in an application. I have added a new functionality to an old and busy form made of different tabs (and tabs within tabs).

When I drop a TTMSFNCTreeView on the form, all seems normal but as soon as I run the application and shows the form, the node's expand/collaps image disapears (as if the NodeAppearance.CollapsedNodeIcon* and NodeAppearance.ExpandNodeIcon* properties where set to nil).

So, I replaces the stock images with new one in BPN format and, instead of "nil" behavior, I get black squares.

I don't have this behavior in a new, blank form.

What could be the cause of this?

This seems very strange, can you send a sample so we can investigate this here?

Not easily: the app is pretty large and I cannot reproduce it with a test app.

I have one suspicion, though: we have (very old) classes that implements PNG and GIF file formats (dating back from the Delphi 6 years). We have to keep them in the application because we build a report builder that uses delphi's form serializing mechanism the the result is not 100% compatible with the new delphi classes that handle these types. (We have to keep them in because customers have created reports containing reference to these classes and removing them breaks these reports).