Hi David,
I'm afraid it's a little too hard to guess based on your descriptions; I
think you'll have to post the code.
One bit of code you did post had to do with the tree being expanded with 10
more items every time you tabbed away and back to it; you posted:
If DialogCreated Then
This looks like you're using a variable to track this which isn't getting
reset; it's better to test on the event = dialogCreated rather than testing
on a variable you have.
Yes, I too have had problems which occur because I am doing something every
time the dialog event handler is being called, even when it was being called
because the dialog was closing (which caused me problems), so yes, you have
to test on whether the event indicates the dialog is closing.
Hth,
Chip
From: David [mailto:[email protected]]
Sent: Wednesday, January 29, 2014 7:08 AM
To: [email protected]
Subject: Treeview experience, some interesting observations
Listers,
I have been playing around with the Treeview in a couple of my projects
lately. And, I have been looking at a few Apps, to get the idea of how to
handle the Treeview. Things basically are up running by now, but I have made
a couple of interesting observations. I wonder if I am misunderstanding
something, or if there is a whole in my knowledge. Likely some of you, have
made similar experiences.
First of all, I made a Dialog in the XML, holding a Treeview, and two
buttons - like an OK, and a Cancel button. Things got more advanced later
on, but for now, let's concentrate on this basic Dialog.
Next, back to the code, and build a Queued sub, to call the Dialog Handler
function of the Treeview Dialog. All that, worked just fine, and I got
things to display on the screen.
Now was the time, to start fill in the information in the Treeview. The info
I needed, was all stored in a file on the computer, so to retrieve it, and
have it correctly filled into the Tree, was quite easy. After all, the
treeview I am working on in one project, only holds the Root, and some
entries in the first Child level.
To make all the filling of the tree easy as possible, I placed all of that
processing stuff, in a sub, called "FillTree". I pass the Treeview object,
as the parameter to the sub, from inside my Dialog Handler. Something like:
FillTree DObj.Control( "MyTreeview")
DialogHandler = True
Exit Function
Fine. The Treeview gets filled, with something like ten entries in the Root,
and anything from one to ten entries in the first sublevel for each Root
entry. All as expected. Yet, now comes my observations.
Running the app, the Dialog opens, and you land on the Treeview. The
FillTree routine has been called, so your screen will show a treeview, with
ten entries in the Root. You now try to tab to the OK button, and then tab
back to the Treeview. What do you think, other than now your treeview will
hold twenty entries in the root. Perform the act ten times, and your entries
will be tenfold in the root. OK, I see what is the case, everytime I land on
the treeview, the FillTree sub is called, causing it to add on the same
entries all over, thereby raising the number of entries. The stuff is basic
enough this far.
My question number one to all of you experienced ones, is:
Where in the Dialog Handler should I perform the FillTree call?
I thought, based on primitive thinking, that I could place it near the end
of the Handler. There, I have a section like this:
Case Else
If DialogCreated Then
FillTree DObj.Control( "MyTreeview")
ElseIf DialogClosing Then
BlahBlahBlah
Since I reasoned this section would only be effective when the Dialog was
all created, I thought this would be the place to fill in the Treeview. Yet,
it seems for some strange reason, that I was wrong. My testing has revealed,
that the stuff in the above samplified section, will be executed on each
move I make in the Dialog, and thereby keep "filling things into the
treeview", whenever I tab around.
OK, I figured one solution, in that I let the FillTree sub, start out by a
Clear command, to start with an empty treeview, and refilling it from
scratch, everytime the call comes. But, that also lead to another issue, as
now I will keep ending up at the top of the treeview, everytime I tab away,
and back to the tree.
I further figured, that I could store the selected Node, at any given time,
and let the FillTree sub conclued every run, by focusing the stored
selectedNode. That works just fine, long as I am in the Dialog operating.
And, if I hit the Cancel button of the Dialog - which simply cause a
DObj.Close
call inside the Dialog Handler, the stuff may work in some cases. What
happens, is that long as I am focusing the root of the treeview, then
hitting the Cancel button, things close troublefree. But, when I have
expanded one of the Root Nodes, and focused a Node on the first sublevel,
then hit the Cancel button, the dialog close, and the screen reader crashes
altogether. It actually crashes that much, you get this three-note tiny
tune, and the computer hangs for several minutes, before Window-Eyes let go
of the system - a behavior that in general is a clear drawback of WE. OK, my
question number two, for you guys, is:
Do any of you have a clue what could cause this kind of crashing, just
because a Child Node is focused, when the dialog is being closed?
It even happens, if there is no other activity going on, as a direct result
of the Node being focused. Just this simple sample I here have described.
Whether it is because I need to erase any objects before closing the Dialog,
or If I am missing some essential point, I am not aware. Yet, I did try two
things, with no further success.
First, I started out the FillTree sub, by a line, indicating that if the
parsed object - from the Dialog Handler - is empty the sub should exit
immediately. My hope was, that no other attempt to fill in a closing
treeview, would have fixed the trouble of crashing. Next, I tried to set the
treeview control to nothing, as part of the closing routine in the Dialog
Handler. None of it worked to my satisfaction.
Finally, I thought, maybe it could be due to the FillTree sub trying to
focus the selected node, upon each redraw of the treeview. OK, so I removed
that line in the sub, and now it seems not to crash, whenever I close the
Dialog. OK, any ideas as to if I could have worked around all that closing
trouble? Should I have erased any further objects, or how can I make the
user selected node focusing all the time, and still have the dialog closing
properly? Not even On Error Resume Next, would work for troublefree closing.
And, as stated above, how can I prevent the treeview from refilling
everytime you tab back and forth in the dialog?
Sorry for the rather long explanation. Hope someone have had some experience
and found working ideas. As I said, I have looked at other codings, and
thought I had done much of the same procedures as the rest of you. Yet, all
this trouble. Smile. What really puzzles me, is why things in the
DialogCreated section, keep repeating for each tabbing around. Maybe I am
misinterpretting that instruction, but I thought it would only fire, when
the Dialog is initiated, hence I could perform a "one-time" action in that
section. Apparently not, so any other ideas are welcome.
thanks,
