by Wolfgang Schoenberger (1 Submission)
Category: Coding Standards
Compatability: Visual Basic 5.0
Difficulty: Intermediate
Date Added: Wed 3rd February 2021
Rating: 
(11 Votes)
This handy little procedure will handle all child Checkboxes in a TreeView control. If you check a parent node it will automatically check the child node(s).
The procedure is called recursivly.
VBcoders' Add this procedure to your source code
Private Sub process_check(node As node, ch As Boolean, frst As Boolean)
' ch = True or False, depending of the first node
' frst is True when the procedure is called for the first time
' otherwise frst is always false
Dim n As node
Dim n2 As node
' If the current Node has no children and procedure is called 1st time
' just check the node and exit
If node.Children = 0 And frst Then
node.Checked = True
Exit Sub
End If
Set n2 = node
While Not n2 Is Nothing
' If the node has children
' check the node and call process_check recursivly with the first child node, ch
' and False as frst parameter
If n2.Children Then
n2.Checked = ch
process_check n2.Child, ch, False
' If procedure is called 1st time, set n2 to Nothing, so that Loop can end
' otherwise set n2 to the next sibling node
If frst Then
Set n2 = Nothing
Else
Set n2 = n2.Next
End If
' If node has no children, check the node and set n2 to the next sibling node
Else
n2.Checked = ch
Set n2 = n2.Next
End If
Wend
End Sub
' You can call this procedure from your node_check event.
' Exmaple
Private Sub TV1_NodeCheck(ByVal node As MSComctlLib.node)
process_check node, node.Checked, True
End Sub