Big VB6 Project Mystery

[baron]

I would appreciate any advise regarding the following mystery:

I migrated every single label in a massive VB6 project to use the LblCtlsLibUCtl.WindowlessLabel control instead of VB.Label (it was not easy - it took a whole day). Once this is done, I see that I can no longer run the project - it is stuck on 100% CPU for over ten minutes every time I either try to run it from inside VB IDE, or try to compile it. So I experimented as follows:

- I tried a simpler project with only a few of the same forms and controls. It loaded fine.

- I tried adding more and more forms and controls from the above project. Every form/control I added made it slower and slower. In other words this stuck/waiting period became longer and longer the more forms and controls I added (Although it did run fine once this period was over). I stopped adding forms when it reached about six minutes. So basically I understood from this that the above complete project was not stuck, it was just working hard for ten minutes until I killed it.

- Note that this identical huge project worked perfectly fine before I switched label controls.

- I tried downloading an old version of LblCtlsLibUCtl and ran the project with it, but this didn't help.

- I thought that maybe it had to do with the amount of labels in a single project so I made an empty project with about 6000 labels in 100 forms. But this worked fine.

Any ideas on what I could test next? Is there anything in the label control that could make the IDE work really hard when it runs or compiles? Perhaps it has to do with where the controls are placed, or interactions with other controls/containers, or specific methods/events that are used on the controls?

[TiKu]

This sounds really strange. How many Forms and WindowlessLabel controls are we talking about?

[baron]

Hundreds of forms and controls, about 1000+ labels scattered in various ways in most of them. But it's not the number of labels as my experiment proved. Unless there is a difference between labels in an control array or not. Or unless there is a difference on WHERE I place the label.

[TiKu]

Can you provide a sample project that demonstrates the problem?

[baron]

Nope, not yet because I have no clue how to reproduce it outside of this huge project. And I can't send this huge project obviously which isn't mine to send. I'll continue experimenting tomorrow with a few combinations but its going to be painful and I could really use some advise on where to start looking.

[TiKu]

You could install Sysinternals Process Explorer and have a look at the process' stack trace while it hangs. Maybe it gives you an idea of what is taking so much time.

[baron]

I found it. I had missed a few event handlers that didn't match the event parameters of your label controls (e.g. Click with a control array). This was still weird behaviour for the IDE since it usually just pops up an error instead of freezing. But this was the cause and it now works fine. There are many differences between the VB.Label and this label control which makes it quite tricky to migrate a project like this.

In any case, thanks for the support.

[TiKu]

You're welcome.