I have a VB6 app that is using DBGrid32.ocx as an unbound grid.  The app has
been running fine for a while but I started to see a problem on machines
running XP with SP2.  The user enters values into cells in a row.  When they
move off the row, the new values are saved to the database.  It all works
fine except on XP/SP2.  The new values are saved correctly to the database
but the old values are redisplayed in the old row as focus moves to the next
row.

I recently installed SP2 on my XP development machine to try to figure out
what was going on and I ran across something strange.  On my machine running
XP/SP2, if I run the application from within the VB6 IDE it runs fine.  I
don't see the display problem in the grid.  On the same machine, if I
compile the application and run the exe, I see the display problem.

I'm not sure what this means.  It's obviously going to be processing
something differently from the IDE compared to a compiled EXE but I don't
know exactly what.  I would assume if the app is running on the same machine
it would using the same libraries and dells regardless of whether it is
running from the IDE or from a compiled EXE.  Anyone have any ideas about
what is going on here?

Thanks!
Terry

thoughts were released on Tue, 24 May 2005 08:17:20 -0500
bearing the following fruit:

Show quoteHide quoteHard to comment on your precise problem but yes it does
behave differently in the IDE and compiled app.

Timing is different for one thing and that fraction of extra
time it takes to do something in the IDE over a compiled app
can indeed cause it to behave differently, perhaps a refresh
doesn't happen or an even doesn't fire.







Jan Hyde (VB MVP)

I was hoping that I'd be able to step through the app in the debugger to
pinpoint the spot where previous values in the grid are restored so I was
disappointed and somewhat surprised when everything worked correctly.  I
guess I'll have to try writing debug lines to a log file, although I suspect
that could possibly effect timing also. Strange, I've never run into this
before.

thoughts were released on Tue, 24 May 2005 09:27:34 -0500
bearing the following fruit:

It could but thats the techneque I use and it's worked for
me so far.

LOL, you must be lucky, we've hit it dozens of times each.





Jan Hyde (VB MVP)

You can try using the VC debugger, if you have it. In the VB project
settings, select the option "Create symbolic debug information", then create
an EXE.
In the VC debugger, select "Open Workspace", select the EXE of your app, and
manually open any (VB) source files you need. Then you can set breakpoint.
There are some severe limitations, e.g. you cannot view all variable values,
but you can see which path the program takes, and view some variable values.

Robert

Show quoteHide quote

I didn't know you could do that.  I'll give it a try.  Thanks Robert!

In case anyone is interested I found a workaround to my problem.  I don't
know what is causing the problem exactly but I can get the app to work
consistently now at least.

The app is using the dbgrid32 control as an unbound grid.  According to the
help file, setting the bookmark property to itself will force the current
row to be updated through the UnboundWriteData event.  I did this in the
grid's AfterColEdit event and the display problem went away.  I am not sure
what changed with XP/SP2 that now requires this but it took care of the
problem.  The display worked fine in W98 and XP/SP1 without this line.

However, there seems to be a side-effect of this change that I now need to
deal with.  Since I've added the line to set the bookmark property to
itself, the grid is acting slightly differently.  Whenever I edit a column
and then move to a lower row, the grid scrolls everything so the row I just
edited is now the top visible row in the grid.  This now happens only on
XP/SP2.  I have the same EXE running on a machine with XP/SP1 and the grid
does not automatically scroll the rows as you edit them.  This is only
happening with XP/SP2 and has only started to happen since I added the line
to set the bookmark to itself. If I remove the line to set the bookmark, the
scrolling issue goes away.

I'm just starting to look into this.  If anyone has any suggestions for the
scrolling issue, I'd appreciate hearing them.

Thanks
Terry

Generating Trees for Data
Need some help in compressing bmp file to jpeg file
Get rid of flicker inside a frame.
UDT question
Installing Fonts
using user defined types
VB to MySQL connection
DateSerial overflows
ActualSize returns -1
AD Info od User or Computer