BUG: Wrong TreeView Node Selected When SingleSel Property = True

• Microsoft Visual Basic Professional and Enterprise Editions, 32-bit only, for Windows, version 6.0

SYMPTOMS

When using the Microsoft Visual Basic 6.0 service pack 3 (SP3) version of the TreeView Control, in a project with the SingleSel property set to True, when you click a node sometimes a different node will be selected and expanded.

RESOLUTION

To work around the problem set the SingleSel property to False and implement the SingleSel functionality with your code.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

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.

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.

Additional query words:

Keywords : kbsample kbCtrl kbTreeView kbVBp kbVBp600bug kbGrpVB kbDSupport
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbbug