Modal windows not frontmost

[Intaris]

I and many others have been having troubles with the Z-ordering of LabVIEW's windows for some time.

While up until now it was mainly a nuisance it now has be angry.  I've experienced several times that a window which SHOULD be modal is appearing BEHIND other windows, essentially making my work with LabVIEW impossible bec ause none of the other windows respond and without mouse access to the actual modal window to close it, I have no point of entry to conttrol my software.  Looks like a deadlocked process when it's really the window management which is at fault.

I'm currently looking at exactly such a problem in fromt of my eyes.  I'm not doing anything with win32 DLLs.  Running LV 32-bit on a 32-bit WinXP in a VM.

Anybody else seeing this?

[Yamaeda]

Yeah that has happened quite a few times. If you alt-tab to other windows or get a 2nd modal window (e.g. a error popup) seems to cause the issue. Quite annoying at times! Sometimes you can get the dialog back by alt-tabbing to another window and back, or activate it in taskbar or similar, but i haven't found any 100% workaround.

/Y

[MarcoMauri]

I've seen that, too.

Is this a Labview related problem or a Windows-related one?

Marco

[TamMou]

Hi all,

Could you tell me when does this problem appear specifically since it does not seem to be systematic. What are the other windows hiding your desired modal window?

The first points to check would be :

- make sure that the top (inappropriate) window isn't set as a modal
- did you use property nodes Is Frontmost?

There is also another way to change the frontmost property that has to be checked:

http://digital.ni.com/public.nsf/allkb/4DA4C9C8D65A6834862576620050648E?OpenDocument

[rolfk]

I have seen similar situations and it seems related to Windows 7 or newer. Never had such an issue on XP or earlier. And I believe it is a combination of Windows doing some "smart" behind the scene operation that bites with something LabVIEW is doing in its own window management handling. There seems to be some intermediate Z layering management layer in LabVIEW that implements the floating behaviour of Windows to match MacOS semantics. It is probably interfering somehow with a change MS did in recent Windows window layering handling.

[Intaris]

To clarify,

the windows which end up being blocked are normally simple OS File selection windows (Like when you want to select a file).  If you have one of these open and can't access the window, then it's time to hit ctrl-alt-delete.

I also never saw this problem under XP.

Shane.

[TamMou]

Yes, apparently, this modal windows problem is generally encountered with Windows 7 and is not coming from LabVIEW:

http://stackoverflow.com/questions/8367700/modal-windows-appearing-behind-others-in-windows-7

http://www.opengl.org/discussion_boards/showthread.php/170214-Windows-7-fullscreen-OpenGL-Modal-dial...

[Intaris]

---

@TamMou wrote:

Yes, apparently, this modal windows problem is generally encountered with Windows 7 and is not coming from LabVIEW:

http://stackoverflow.com/questions/8367700/modal-windows-appearing-behind-others-in-windows-7

http://www.opengl.org/discussion_boards/showthread.php/170214-Windows-7-fullscreen-OpenGL-Modal-dial...

---

So there's no change of the LV environment being aware of this and simply taking steps to avoid it?  This is a big problem.

[TamMou]

Yes, this is not ideal and I am still looking for a way to solve this issue. But, in order to eliminate a problem coming from LabVIEW, you can send me your VI so that I can check it.

[Intaris]

It's not a VI, it's an entire project which is rather large.  I don't think sending the project is possible, but I'll see if I can get a cut-down version to post.