Hi David,
The text in the tree view is the stuff you see being said on the tree. The
data, is the ID tag for that item selected.
Now, when you go down another level, you deciding the data to reflect the
level.
Suppose you have on the main list 10 items, OK?
Then on the second level you have no more than 10 items, OK?
The the third level you also have 10 items, OK?
Now you are dealing with powers of 10, or 0 to 9. So, you have 3 levels so
each ID tag of each level would be a power of 10, or if your selected item is
19, OK?
Then you are item 1 of the first level and the 9'th, actually 10'th item of
the second level, OK?
This is how you set your check box, which does not exist, but the tree
view, or limb you follow is the value of the data item at that point.
This is what I had sent you and yes, what I sent you is confusing, but the
guts of that is the beginning of the MainProc where I start doing that level
check; but you have to understand my program to get there.
so, as I have mentioned above, set your data value to show the full amount
of data, checks at the tree view level you are opened up to.
In this case you only have one item selected at each level and that is all
you can do in a tree view, but since you are selecting a sub value of a main
level, you do not need anything more than that. For that is the meaning of a
tree view, following a tree limb...
I hope this helps. I will send or post the tree view items and how to make
them, there are only 2 or 3 places where that happen, one place where the main
menu is made into categories, then the listing of file names or programming
names in the second level, and the third level is the info supplied for each
program. This is what I did in the UnInstall program.
So, the text is what is displayed and said when you move through the tree
view, the data is the ID tag for each and every item on the tree and you make
up the rules for that.
As I said, using the power of 10 only allows 10 items for each sub level.
You can expand that as I did to indicate up to a 1000 at each level which means
you are going down each level as a power of 3 each. You can make it even large,
each call to the subroutine must reflect that choice.
But ID tags can be words as well if you choose to do so...
I hope this helps, next I will send the exact 2 programs that do this for
you, along with the controlling top level loop...
Sincerely
Bruce A. Babcock
Sent: Thursday, April 11, 2013 7:18 PM
Subject: Re: Treeview Questions - Still attempting to learn :)
As regards to my prior message, I have solved issue number 3, how to quickly
iterate
the whole tree-structure. Still, my other questions remain open.
But for what it is worth, and to all who might benefit from a quick way of
running
through all the possible items on a tree, here I am pasting in the sub
routine, that
will do the whole iteration. It is not more than a few lines of coding, and
will
do with any number of branches and leaves, from what I can see. In the pasted
example,
the actual line of interest, is the Speak line, which will read out the Text
property
of the individual item. You can replace this line, with any other activity
you want
performed on the individual item. The sub will take a TreeviewItems object,
as its
parameter. If you want the whole treeview iterated, from root and out, you
could
simply do something like:
IterateTree TreeviewObject.TopLevel
Where TreeviewObject is an object pointing to a treeview, that you have
defined.
In my testing app, I called it from the DialogEventHandler function of my
testing
dialog. Here I have defined a treview control, named TV_Test, and the sub is
called
when a button "BTN_SpeakTree) is pressed. The snip-it of the
DialogEventHandler then
looks like this:
Case "BTN_SpeakTree"
If DEvent = ButtonClicked Then
IterateTree DObj.Control( "TV_Test" ).TopLevel
DialogEventHandler = True
Exit Function
End If 'BTN_SpeakTree.
And, here is the iteration sub:
Sub IterateTree( TVItems)
Dim CurrentItem: Set CurrentItem = Nothing
Dim ItemNumber
For ItemNumber = 1 To TVItems.Count
Set CurrentItem = TVItems.Item( ItemNumber)
' The following line, is the actual action, performed on the individual item.
Replace
it with whatever you want:
Speak CurrentItem.Text &","
If CurrentItem.Children.Count >=1 Then
IterateTree CurrentItem.Children
Set currentItem = Nothing
End If 'CurrentItem.Children.Count >=1.
Next 'ItemNumber.
' Room Cleaning:
If Not CurrentItem Is Nothing Then Set CurrentItem = Nothing
If Not TVItems Is Nothing Then Set TVItems = Nothing
End Sub 'IterateTree.
Hope all of this will be of any help for the rest of the community. I am
sure, things
can be modified to work even more smoothly, and that you can change whatever
part
of it, to fit your personal scripting needs. But at least, I wanted to share
this,
since it is not something that first comes to mind, how to handle. Enjoy it.
And
if anyone has any feedback on the other issues I presented in the initial
message
of mine, I am all greatful for whatever feedback you may have.
Thanks again,
----- Original Message -----
From:
David
To:
[email protected]
Sent: Thursday, April 11, 2013 11:14 PM
Subject: Treeview Questions - Still attempting to learn :)
I am still trying to wrap my brain around the complexity of a treeview, and
how to
gain the fullest benefit from this kind of control. Earlier, when asking, one
of
you send me a code snip-it from one of his apps, holding some 600 lines.
Thanks to
you, and it got me somehow going. Yet, I don't follow all of your thinking,
or the
reason why you do this and that. That is one of the drawbacks of 600 lines of
coding.
Smile.
Allright, I have got that far, that I am able to fill in the information on
the tree,
and get it displayed in my dialog. So far, this works satisfactory. Now, I am
stuck
with a few challenges, most of all when comes to retrieve the needed
information
from the treeview. I have a feeling, most of my getting stuck here, is due to
a lack
of understanding. That's why, I hoped to have some clarification on the
following
questions.
1. What is the exact benefit of the Text, as compared to the Data, field in a
treeview
item. OK, I do get the fact, that in case the same text could happen to be on
several
branches or leaves of the tree, the Data field could be used to distinguish
the one
occurrance from the other. But if i have a tree, where no text will appear
more than
once, is there any reason why I should bother about filling in the data field
for
each item? I.e, would there be any search feature or the like, that could be
quicker
done by iterating the tree-structure on the Data fields, compared to simply
just
concentrating on the Text fields.
2. The treeview I am building, has checkboxes, which the user can check for
each
item on the tree. I have searched the Reference manual, but not sure if I
have overlooked
anything. From what I can see, there is no way in determining whether a
treeview
Item has been checked or not. I see the Selected feature, but from what my
testing
leads me to understand, this simply let's me know when an item has focus
(that is,
when the cursor is placed on the item, the Selected feature will be set). Is
it correct,
that there is no build-in feature, that would "fire", when a treeview item
has been
checked or unchecked? If this is the case, technically, why? We have features
for
Checkboxes, which will tell us when it is checked and not - and we have
similar features
for a multi-selection listbox. Why would there be no feature set, whenever a
treeview
item is checked?
3. Does anyone have a simple quick iteration routine, for "rushing" through a
whole
treeview, including all its branches and leaves. My treeview, might hold as
much
as 9 sublevels, in addition to the root. And it might hold different amounts
of entries
on each branch or sublevel. I guess the best would be to use some For...Next
loops,
and somehow retrieve the Count property for each branch. But I have run my
head into
the wall, as to how to get through absolutely all the possible items on the
tree.
I guess, that is the one way to go, when iterating the different items, or am
I totally
lost in such an approach? Say for instance, the user would have been given
the chance
of searching for a given text, which would be the Text property of an item on
the
tree. I then guess, I will have to iterate all the current items on the tree,
looking
out for that particular text. And, that is why, I wondered if there was a
simple
routine, that would perform such a "run-through", with relatively few lines
of coding.
Yep, I did read through I don't know how many pages, in the Reference manual,
and
I have been looking through quite a few lines of existing coding. I am sure,
I can
get on with this, if only I can wrap myself around a few corners. So, anyone
who
has the urge to help me on getting those pieces of information straightend
out, thanks
to you, as it surely will help me crawling my way further on. :) Only hope my
questions
were clearly enough stated, that you will be able to give me the right push.
:)
