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How to detect checkbox changes in a TreeView?


syntech
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Hello!

I would like to know if it is possible to detect checkbox changes in a TreeView without checking every single TreeViewItem? Or how can I find out if a TreeView has the focus? At the moment I'm consistently checking all TreeViewItems for changes, but this is very bad for the performance. That's why I would like to know if the TreeView is in use or not, because if not, then I can skip the iteration through all items and do it only when the user is actually 'using' the TreeView. Any suggestions?

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whatever Edited by MvGulik

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Take a look at the _GUICtrlTreeView_Create() example in the help-file (note that you'll have to replace some const figures by adding an A if they're found undeclared: e.g. $TVN_DELETEITEM => $TVN_DELETEITEMA). Using WM_NOTIFY you can detect if the treeview has been accessed and what has been done. As far as I can see these two:

$NM_CLICK

$TVN_KEYDOWN

can be used to change checkbox state, either by mouse or keyboard. If you detect one of them, issue a _GUICtrlTreeView_GetChecked() command on the respective control handle and save the states to an array representing your treeview states... no need to loop anymore :D...

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[..]Using WM_NOTIFY you can detect if the treeview has been accessed and what has been done. As far as I can see these two:

$NM_CLICK

$TVN_KEYDOWN

can be used to change checkbox state, either by mouse or keyboard. If you detect one of them, issue a _GUICtrlTreeView_GetChecked() command on the respective control handle and save the states to an array representing your treeview states... no need to loop anymore :D...

This sounds very intersting, too! Thanks also to you for your suggestion. I've never used WM_NOTIFY before, so I'll check what it can do for me. :huggles:
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This is strange... Is _GUICtrlTreeView_GetChecked() broken or returns true in case of false and vice versa? Because when I check the box and output the return value of _GUICtrlTreeView_GetChecked() it says false. When I de-check the box it returns true... According to the help file it should return true for checked boxes and false for unchecked boxes. Is this a known issue?

edit: I'm using Version 3.3.4.0 (the latest release)

Edited by syntech
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Works fine for me...

#include <GuiConstantsEx.au3>
#include <GuiTreeView.au3>
#include <GuiImageList.au3>
#include <WindowsConstants.au3>

Local $hItem[6], $hRandomItem, $hTreeView, $edit, $string
Local $iStyle = BitOR($TVS_EDITLABELS, $TVS_HASBUTTONS, $TVS_HASLINES, $TVS_LINESATROOT, $TVS_DISABLEDRAGDROP, $TVS_SHOWSELALWAYS, $TVS_CHECKBOXES)

GUICreate("TreeView Get Checked", 620, 300)

$edit = GUICtrlCreateEdit("", 400, 10, 200)

$hTreeView = GUICtrlCreateTreeView(2, 2, 396, 200, $iStyle, $WS_EX_CLIENTEDGE)
GUISetState()

_GUICtrlTreeView_BeginUpdate($hTreeView)
For $x = 0 To UBound($hItem) - 1
    $hItem[$x] = GUICtrlCreateTreeViewItem(StringFormat("[%02d] New Item", $x + 1), $hTreeView)
Next
_GUICtrlTreeView_EndUpdate($hTreeView)

; Loop until user exits
Do
    Sleep(500)
    $string = ""
    For $x = 0 To UBound($hItem) - 1
        $string &= "Item " & $x & " is checked: " & _GUICtrlTreeView_GetChecked($hTreeView, $hItem[$x]) & @CRLF
    Next
    GUICtrlSetData($edit, $string)
Until GUIGetMsg() = $GUI_EVENT_CLOSE
GUIDelete()
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@KaFu:

I found the problem. I was checking to early. I added the test to the $NM_CLICK case, but at this time the checkbox is not really set yet. Now I have to find out when I can add my routine, because $TVN_SELCHANGE does not work either, because I can select the checkbox of item 2 but item 1 is still highlighted, therefore no selection change has happend and the case is not true. I'll look if there is a possibility to make a selection change when I only click into the checkbox. Then it should work I hope.

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I took a deeper look... and it's much more complicated then I anticipated in the beginning :D... take a look into my ShellTristateTreeView (see sig), there I use some code based on Holgers work to check the states.

Is it really necessary to monitor each change? Alternatively you could wait for the message $NM_KILLFOCUS and then loop through all items to check if they're checked.

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[..]Is it really necessary to monitor each change? Alternatively you could wait for the message $NM_KILLFOCUS and then loop through all items to check if they're checked.

Well, I wanted to react to every checked TreeViewItem the moment it is checked/unchecked. But I'll try it with $NM_KILLFOCUS, maybe it's good enough... Edited by syntech
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