The Treeview Drag&Drop AND using custom TreeNode !

Here is the code that I use to  carry out a drag & drop on my TreeView, it goes very well !
but when I use my own custom TreeNode (named : 'UsrTreeNode' and have some properties added) instead of the original 'System.Windows.Forms.TreeNode' , the drag & drop do not have any effect.
I tried doing something like :

1) My own custom TreeNode.

<Code>
Public Class UsrTreeNode

    Inherits System.Windows.Forms.TreeNode
    Private NodeType As String

   Public Sub New(ByVal [text] As [String], ByVal [Id] As [Double], ByVal [ImgIndx] As Integer, ByVal [SelImgIndx] As Integer)

        MyBase.New([text],[ImgIndx], [SelImgIndx])
        MyBase.Tag = [Id]
    End Sub

    Public Property Type()
        Get
            Return NodeType
        End Get
        Set(ByVal Value)
            NodeType = Value
        End Set
    End Property
End Class
</Code>

2) My DragDrop event :

If I populate my TreeView with my custom UsrTreeNode instead of original TreeNode and use the same code (by replacing Treenode by UsrTreeNode)  my drag and drop doesn't work and no error raised !!

<Code>

Public Sub TreeView_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles Trv.DragDrop

        Dim NewNode As UsrTreeNode

      '----If e.Data.GetDataPresent("System.Windows.Forms.TreeNode", False) Then

       If e.Data.GetDataPresent("MyApp.UsrTreeNode", False) Then
            Dim pt As Point
            Dim DestinationNode As UsrTreeNode
            pt = CType(sender, TreeView).PointToClient(New Point(e.X, e.Y))

            DestinationNode = CType(sender, TreeView).GetNodeAt(pt)

            'NewNode = CType(e.Data.GetData("System.Windows.Forms.TreeNode"), TreeNode)

            NewNode = CType(e.Data.GetData("MyApp.UsrTreeNode"), UsrTreeNode)

            'DestinationNode.Nodes.Add(NewNode.Clone)

            DestinationNode.Expand()

            'Remove original node
            NewNode.Remove()
        End If
    End Sub

</Code>

Any idea.

Thanks

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The Treeview Drag&Drop AND using custom TreeNode !

venkateshwar rao gundlapally
You have reson Jacob, in fact, the step by step Debug revealed the culprit of the twice copy ! it's my Sub BeforeExpand_expand on which I point after the : DestinationNode.Expand(). Thank you Jacob for your assistance, it works very well now. I'a very satisfied.
Bryan St. Amour
That works fine by using the Overrides Function Clone, but if I drag&drop a node, I have all its children nodes in double (copied twice) !!

(I use : DestinationNode.Nodes.Add(NewNode.Clone) to add my NewNode CLONE to my TreeView)
ngc
That's really strange... It looks like you have code running through the child nodes twice. Are you, perchance, looping through all the children of the nodes and calling Clone on them rather than just cloning the parentNode Based on the code you have posted, it certainly doesn't look like it . . . The clone method I posted is something I have used in a number of projects and I have never had a problem like this . . .
Trevor Hancock MSFT
I think that the recursive part of the method must be, it allows to have all children cloned (with all new propoerties as I want).
but here is what happens :

before grag&drop :

ParentNode
      |_______ Child_1
      |_______ Child_2
      |_______ Child_3

After Drag&Drop to a DestinationNode  i obtain :

DestinationNode
......|
......|__ Parent node
.................|_______ Child_1
.................|_______ Child_2
.................|_______ Child_3
.................|_______ Child_1
.................|_______ Child_2
.................|_______ Child_3

Instead of :

DestinationNode
......|
......|__ Parent node
.................|_______ Child_1
.................|_______ Child_2
.................|_______ Child_3

how I can remove doubled nodes
Oyster Poh
Excellent... Glad it worked out.
FrdBed
What happens when you add the second parameter to the GetData method This works for me in my world of custom treenode drag-drop:

NewNode = CType(e.Data.GetData("MyApp.UsrTreeNode", True), UsrTreeNode)

Of course, it's also useful to make sure that your Type string is fully qualified and you don't have a phantom namespace somewhere.
porov
Not sure if your code above is an exact copy of what you are using, but the code that you have to add the NewNode to the DestinationNode is commented out . . .
Mark Phillips
The clone method that I posted clones all children nodes as well.  So, when you add the cloned parent node, it will have all of it's children as well...  If you don't want that, then you can take out the recursive part of the method:

Public Overrides Function Clone() As Object
    Dim CloneNode As YourNode = New YourNode()

'copying my properties
    CloneNode.Prop1 = Prop1
    CloneNode.Prop2 = Prop2

    Return CloneNode
End Function
Andr&#233; Alves
After deleting of the sub New (...) in my UsrTreeNode Class, I can perform a drag&Drop now on my TreeView. So, The GetData retreive my NewNode without problem, but at : NewNode.clone I loose the TreeNode Type property witch I have defined for my custom TreeNode !
Here is my UsrTreeNode Class :
<Code>
Public Class UsrTreeNode
Inherits System.Windows.Forms.TreeNode

    Private NodeType As String
    Public Property Type()
        Get
            Return NodeType
        End Get
        Set(ByVal Value)
            NodeType = Value
        End Set
    End Property
End Class
</Code>

and here is my Drag&Drop sub :
<Code>
Public Sub TreeView_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles Trv.DragDrop

        Dim NewNode As UsrTreeNode

        If e.Data.GetDataPresent("GPI.UsrTreeNode", False) Then
            Dim pt As Point
            Dim DestinationNode As UsrTreeNode
            pt = CType(sender, TreeView).PointToClient(New Point(e.X, e.Y))

            DestinationNode = CType(sender, TreeView).GetNodeAt(pt)

             NewNode = CType(e.Data.GetData("GPI.UsrTreeNode",True), UsrTreeNode)

            DestinationNode.Nodes.Add(NewNode.Clone)

            DestinationNode.Expand()

            'Remove original node
            NewNode.Remove()
        End If
    End Sub
</Code>

Any Idea please
mjt
Sorry, I forgot to omit the comment on : [DestinationNode.Nodes.Add(NewNode.Clone)]

the code that I use is as follows:
<Code>

Public Sub TreeView_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles Trv.DragDrop
        Dim NewNode As UsrTreeNode

       If e.Data.GetDataPresent("MyApp.UsrTreeNode", False) Then
            Dim pt As Point
            Dim DestinationNode As UsrTreeNode
            pt = CType(sender, TreeView).PointToClient(New Point(e.X, e.Y))
            DestinationNode = CType(sender, TreeView).GetNodeAt(pt)

           NewNode = CType(e.Data.GetData("MyApp.UsrTreeNode"), UsrTreeNode)

           DestinationNode.Nodes.Add(NewNode.Clone)

           DestinationNode.Expand()

            'Remove original node
            NewNode.Remove()
        End If
    End Sub
</Code>

Thanks.
SMILEMan
Treenode Clone isn't flawless, so you will need to provide your own implementation when using a Custom Treenode as it doesn't automatically copy everything.  Something like this works:

Public Overrides Function Clone() As Object
    Dim CloneNode As YourNode = New YourNode()
    Dim TempNode As YourNode
    If Nodes.Count > 0 Then
     For Each TempNode In Nodes
         CloneNode.Nodes.Add(CType(TempNode.Clone, YourNode))
     Next
    End If

'copying my properties
    CloneNode.Prop1 = Prop1
    CloneNode.Prop2 = Prop2

    Return CloneNode
End Function
The Treeview Drag&Drop AND using custom TreeNode !

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