TColumnComboBox loses ItemIndex (set -1)

VCL TMS VCL UI Pack
1

Hi,
D12, TMS VCL UI Pack XE15

I see with my own eyes that sometimes, on a Windows 10 pc, during the FormCreate all the TColumnComboBox lose their ItemIndex. The ColumnComboBox are popolated at runtime, using a function that adds several values and set the default one; if there is not default value, the function sets the first one (ItemIndex = 0).

As I said before, sometimes on my client's PC, after the FormCreate it takes -1 as ItemIndex, but the ColumnComboBox has the ItemList correctly filled.

Other times, everything works perfectly (same PC, software, user, conditions).

I wouldn't want there to be an event beyond my control that resets ItemIndex to -1 (as it is at design time).
By the way, there is no OnChange event.

Another hypothesis concerns the behavior of the new object included in the D12 version of the TColumnComboBox: a TTimer. It may also explain why this bug only occurs every now and then.

NB: the same software with D11 and previous TMS UI Pack worked correctly.

Thanks in advance

2

Can this be reproduced with the TColumnComboBox demo?

3

I tried to reproduce it with the demo, even releasing a small project to the customer, but unfortunately the demo always worked correctly.

I can't explain it, but my intuition tells me that there is a problem with the management and optimization of events, between FormShow and FormActivate (which can be launched several times), such that at a certain point, despite already having the values loaded, the designtime ItemIndex is set, which is always = -1 (since there are no items)

4

I'm afraid that in order to properly investigate this, we will need details how to reproduce this as so far we have not seen this here and we have not received a similar problem report from other users.