Hi,
I've a very strange problem after upgrading to 12.2.5. Some forms with lot of DevExpress-controls (ribbon, editor, grid, tree, …) when putting them into a parent control like a tpanel or a cxTabSheet raizes an exception "access violation" in unit controls.pas - procedure TWinControl.DestroyWindowHandle; (changing the parent of a form (control) the handles are reallocated).
As said, only certain forms have this problems, others with cxControls works fine. I cannot reproduce the problem with a sample project, so I think it's very hard for you the figure out the problem.
Now I went back to 12.2.4 and the problem disappears. Therefor I'm nearly sure it depends on DevExpress-Controls.
Do you have any ideas what to try else? I would like to work with 12.2.5 since some issue with backstageView of 12.2.4 has been solved.
best regards
Toni
Hello,
I regret to hear that you have faced this problem. Would you please provide us with at least a problematic .dfm file? I will try to reproduce the problem on our side. A CallStack demonstrating the problem would also be much appreciated.
Hi,
I think the problem is not in the dfm (desgin side) but on runtime. Since yesterday I'm trying a lot of things and it seem the problem depends from changing the Visible-property of certain TdxBar-controls in the "OnCreate-event" of the form. If I move this lines of code into the OnShow-event the problem disappears. But I would like to hide certain bars just in the create-event to avoid flickerings and to not have to change to logic of my forms and procedures. My forms are based on the TdxRibbonForm. Not all the forms with similar code have the problem and I cannot reproduce it with a simple sample-project doing similar things.
I don't know if this info is usefull for your.
best regards
Toni
Now I was able to reproduce the problem with a smal sample. See included project. Some project with Vcl 12.2.4 runs without problems. In my "real" application I don't change the Position-property, but the problem seems the same.
best regards
Toni
Hello,
I have tried to reproduce the problem you described on several PCs, but without success. Perhaps, I am missing something. Attached is a video demonstrating how your project works on my side. Would you please clarify whether or not my steps are correct?
Hi Paulo,
your steps are correct.
try to add
if not aFrm.dxBarManager1Bar3.Visible then
ShowMessage('aFrm.dxBarManager1Bar3.Visible is now Visible = false');
in the button1Click-event after
aFrm.Position := poDesigned;
Could be the Visible-flag of the bars don't change on your side. So we have to know why the do here.
my Delphi is Embarcadero® RAD Studio XE Professional Version 15.0.3953.35171, installed on a Windows 7 32bit; all SP and fixes of Windows are installed automatically.
Running the application on WinXP I've the same problem, an "Access violation at address 00000000. Read of address 00000000." is raized. Very strange, isn't it?
Ed Dressel in http://www.devexpress.com/Support/Center/Question/Details/Q489593 seems to have a similar problem.
Toni
Thank you for your clarification. I have reproduced the AV on Windows XP and forwarded this ticket to our developers for research.
Any news in regard? I've to release an official build of my application. Will I've to turn back to previous version 12.2.4?
Our developers are working on this issue. However, it can take us some additional time. Meanwhile I suggest you rollback to the previous version of our controls that works as expected in your scenario because I cannot give you any ETA for now.