Treeview Question

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lothos12345

Junior Contributor
Joined
May 2, 2002
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Location
Texas
Using Visual Basic.Net I have developed an application with a treeview associated with it. When the app loads it loads the treeview with all the pertinent information for both parent and there child elements. The child elements have the same displayname as the parent, except the child has the parent name and a "- child" after the parent name. I want the user to be able to left click on a child element and drag it over to another parent element in the treeview and upon release of the mouse have the child be renamed accordingly with its new parent's name. I am not quite sure how this would look in code. Any help or examples would be greatly appreciated.
 
I found this in Internet, quite useful, doesn't need any modification anyway..

create a treeview named treeview1 and paste this code:

Code: 
Public Class Form1

    Public Sub TreeView1_ItemDrag(ByVal sender As System.Object, _
        ByVal e As System.Windows.Forms.ItemDragEventArgs) _
        Handles TreeView1.ItemDrag

        'Set the drag node and initiate the DragDrop 
        DoDragDrop(e.Item, DragDropEffects.Move)

    End Sub

    Public Sub TreeView1_DragEnter(ByVal sender As System.Object, _
        ByVal e As System.Windows.Forms.DragEventArgs) _
        Handles TreeView1.DragEnter

        'See if there is a TreeNode being dragged
        If e.Data.GetDataPresent("System.Windows.Forms.TreeNode", _
            True) Then
            'TreeNode found allow move effect
            e.Effect = DragDropEffects.Move
        Else
            'No TreeNode found, prevent move
            e.Effect = DragDropEffects.None
        End If

    End Sub

    Public Sub TreeView1_DragOver(ByVal sender As System.Object, ByVal e As DragEventArgs) Handles TreeView1.DragOver

        'Check that there is a TreeNode being dragged 
        If e.Data.GetDataPresent("System.Windows.Forms.TreeNode", True) = False Then Exit Sub

        'Get the TreeView raising the event (incase multiple on form)
        Dim selectedTreeview As TreeView = CType(sender, TreeView)

        'As the mouse moves over nodes, provide feedback to 
        'the user by highlighting the node that is the 
        'current drop target
        Dim pt As Point = _
            CType(sender, TreeView).PointToClient(New Point(e.X, e.Y))
        Dim targetNode As TreeNode = selectedTreeview.GetNodeAt(pt)

        'See if the targetNode is currently selected, 
        'if so no need to validate again
        If Not (selectedTreeview.SelectedNode Is targetNode) Then
            'Select the    node currently under the cursor
            selectedTreeview.SelectedNode = targetNode

            'Check that the selected node is not the dropNode and
            'also that it is not a child of the dropNode and 
            'therefore an invalid target
            Dim dropNode As TreeNode = _
                CType(e.Data.GetData("System.Windows.Forms.TreeNode"), _
                TreeNode)

            Do Until targetNode Is Nothing
                If targetNode Is dropNode Then
                    e.Effect = DragDropEffects.None
                    Exit Sub
                End If
                targetNode = targetNode.Parent
            Loop
        End If

        'Currently selected node is a suitable target
        e.Effect = DragDropEffects.Move

    End Sub

    Public Sub TreeView1_DragDrop(ByVal sender As System.Object, _
     ByVal e As System.Windows.Forms.DragEventArgs) _
     Handles TreeView1.DragDrop

        'Check that there is a TreeNode being dragged
        If e.Data.GetDataPresent("System.Windows.Forms.TreeNode", _
              True) = False Then Exit Sub

        'Get the TreeView raising the event (incase multiple on form)
        Dim selectedTreeview As TreeView = CType(sender, TreeView)

        'Get the TreeNode being dragged
        Dim dropNode As TreeNode = _
              CType(e.Data.GetData("System.Windows.Forms.TreeNode"), _
              TreeNode)

        'The target node should be selected from the DragOver event
        Dim targetNode As TreeNode = selectedTreeview.SelectedNode

        'Remove the drop node from its current location
        dropNode.Remove()

        'If there is no targetNode add dropNode to the bottom of
        'the TreeView root nodes, otherwise add it to the end of
        'the dropNode child nodes
        If targetNode Is Nothing Then
            selectedTreeview.Nodes.Add(dropNode)
        Else
            targetNode.Nodes.Add(dropNode)
        End If

        'Ensure the newley created node is visible to
        'the user and select it
        dropNode.EnsureVisible()
        selectedTreeview.SelectedNode = dropNode

    End Sub
End Class
 
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