FIX: Wrong TreeView Node Selected When SingleSel Property = True

Steps to Reproduce Behavior

1. Create a new Visual Basic 6.0 SP3 Standard EXE project. Form1 is created by default.
2. On the Project menu, select Components. In the Components dialog box, select "Microsoft Windows Common Control 6.0(SP3)" and then click OK.
3. Add a TreeView control to Form1, retaining the default name, Treeview1.
4. Add the following code to the General Declarations section of Form1:

   Option Explicit
   
   Const CHILD1 = "Child1"
   Const CHILD2 = "Child2"
   Const CHILD3 = "Child3"
   
   Private Sub Form_Load()
      Dim strRoot As String
      Dim strChild As String
      Dim i As Long
      
      ' Set Treeview control properties.
      TreeView1.LineStyle = tvwRootLines  ' Linestyle 1
      TreeView1.SingleSel = True  ' Single Selection
      
      ' populate the treeview control
      For i = Asc("A") To Asc("Z")
         strRoot = Chr(i)
         Call TreeView1.Nodes.Add(, , strRoot, "Root-" & strRoot)
   
         Call TreeView1.Nodes.Add(strRoot, tvwChild, strRoot & "1", CHILD1)
         Call TreeView1.Nodes.Add(strRoot, tvwChild, strRoot & "2", CHILD2)
         Call TreeView1.Nodes.Add(strRoot, tvwChild, strRoot & "3", CHILD3)
   
         strChild = strRoot & "1"
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "1", CHILD1)
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "2", CHILD2)
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "3", CHILD3)
   
         strChild = strRoot & "2"
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "1", CHILD1)
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "2", CHILD2)
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "3", CHILD3)
   
         strChild = strRoot & "3"
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "1", CHILD1)
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "2", CHILD2)
         Call TreeView1.Nodes.Add(strChild, tvwChild, strChild & "3", CHILD3)
      Next
   End Sub
   					

5. Run the application by pressing F5. Select a child of "Root-A" in the third level.
6. Select "Root-I". Note that "Root-L" is selected and expanded instead of "Root-I". This behavior is incorrect.

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Steps to Work Around the Problem

1. In the Form_Load() sub, replace the following line:

      TreeView1.SingleSel = True  ' Single Selection
   					

   with

      TreeView1.SingleSel = False  ' Not Single Selection
   					

2. Append the following code to the General Declarations section of Form1:

   Private Sub TreeView1_NodeClick(ByVal node As MSComctlLib.node)
      Call SimulateSingleSel(node)
   End Sub
   
   Private Sub SimulateSingleSel(ByVal node As MSComctlLib.node)
      ' expand current node
      node.Expanded = True
   
      ' collapse all siblings and parents' siblings
      Dim nodeParent As MSComctlLib.node
      Set nodeParent = node
      Do Until nodeParent Is Nothing
         CollapseSiblings nodeParent
         Set nodeParent = nodeParent.Parent
      Loop
   
      ' collapse child's siblings (collapse all children)
      Dim nodeChild As MSComctlLib.node
   
      Set nodeChild = node.Child
      If nodeChild Is Nothing Then Exit Sub
      nodeChild.Expanded = False
      Call CollapseSiblings(nodeChild)
   End Sub
   
   Private Sub CollapseSiblings(ByVal node As MSComctlLib.node)
      Dim n As Integer
   
      n = node.FirstSibling.Index
      If n <> node.Index Then node.FirstSibling.Expanded = False
      
      Do While n <> node.LastSibling.Index
         n = TreeView1.Nodes(n).Next.Index
         If n <> node.Index Then TreeView1.Nodes(n).Expanded = False
      Loop
   End Sub
   					

3. Run the application by pressing F5. It now works as expected.

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