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Copy or Move Nodes from One TreeView to Another Using the CTRL Key

To copy nodes from one TreeView to another, you should make a clone of the dragged TreeNode (sourceNode) and add it to the Nodes collection of the other TreeView. An example is shown below. A hidden field is used to indicate whether a node is being moved or copied.

<telerik:RadTreeView RenderMode="Lightweight" ID="RadTreeView1" runat="server" EnableDragAndDrop="True" OnClientNodeDropping="SaveCtrlState"
    OnNodeDrop="HandleDrop">
</telerik:RadTreeView>
...
<telerik:RadTreeView RenderMode="Lightweight" ID="RadTreeView2" runat="server" EnableDragAndDrop="True">
</telerik:RadTreeView>
...
<asp:HiddenField ID="CtrlKeyField" runat="server" Value="False" />
function SaveCtrlState(sender, eventArgs) {
    var hidden = document.getElementById("<%= CtrlKeyField.ClientID %>");
    if (eventArgs.get_domEvent().ctrlKey) {
        hidden.value = "True";
    }
    else {
        hidden.value = "False";
    }
}
private bool remove;
protected void Page_Load(object sender, EventArgs e)
{
    if (CtrlKeyField.Value == "False")
    {
        remove = false;
    }
    else
    {
        remove = true;
    }
}
protected void HandleDrop(object sender, RadTreeNodeDragDropEventArgs e)
{
    RadTreeNode sourceNode = e.SourceDragNode;
    RadTreeNode destNode = e.DestDragNode;
    if (destNode != null)
    {
        if (sourceNode.TreeView.SelectedNodes.Count <= 1)
        {
            PerformDragAndDrop(sourceNode, destNode);
        }
        else if (sourceNode.TreeView.SelectedNodes.Count > 1)
        {
            foreach (RadTreeNode currentNode in sourceNode.TreeView.SelectedNodes)
            {
                PerformDragAndDrop(currentNode, destNode);
            }
        }
        destNode.Expanded = true;
    }
}
private void PerformDragAndDrop(RadTreeNode sourceNode, RadTreeNode destNode)
{
    if (sourceNode.Equals(destNode) || sourceNode.IsAncestorOf(destNode))
    {
        return;
    }
    // clone the sourceNode
    RadTreeNode sourceNodeClone = CloneNode(sourceNode);
    if (remove == false)
    {
        sourceNode.Owner.Nodes.Remove(sourceNode);
    }
    // add source node as a child of the destination node
    if (!sourceNode.IsAncestorOf(destNode))
    {
        destNode.Nodes.Add(sourceNodeClone);
    }
}
private RadTreeNode CloneNode(RadTreeNode sourceNode)
{
    RadTreeNode clonedNode = new RadTreeNode();
    clonedNode.Text = sourceNode.Text;
    clonedNode.Value = sourceNode.Value;
    clonedNode.ImageUrl = sourceNode.ImageUrl;
    clonedNode.ExpandedImageUrl = sourceNode.ExpandedImageUrl;
    return clonedNode;
} 
Private remove As Boolean
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If CtrlKeyField.Value = "False" Then
        remove = False
    Else
        remove = True
    End If
End Sub
Protected Sub HandleDrop(ByVal sender As Object, ByVal e As RadTreeNodeDragDropEventArgs)
    Dim sourceNode As RadTreeNode = e.SourceDragNode
    Dim destNode As RadTreeNode = e.DestDragNode
    If destNode <> Nothing Then
        If sourceNode.TreeView.SelectedNodes.Count <= 1 Then
            PerformDragAndDrop(sourceNode, destNode)
        ElseIf sourceNode.TreeView.SelectedNodes.Count > 1 Then
            For Each currentNode As RadTreeNode In sourceNode.TreeView.SelectedNodes
                PerformDragAndDrop(currentNode, destNode)
            Next
        End If
        destNode.Expanded = True
    End If
End Sub
Private Sub PerformDragAndDrop(ByVal sourceNode As RadTreeNode, ByVal destNode As RadTreeNode)
    If sourceNode.Equals(destNode) OrElse sourceNode.IsAncestorOf(destNode) Then
        Return
    End If
    ' clone the sourceNode
    Dim sourceNodeClone As RadTreeNode = CloneNode(sourceNode)
    If remove = False Then
        sourceNode.Owner.Nodes.Remove(sourceNode)
    End If
    ' add source node as a child of the destination node
    If Not sourceNode.IsAncestorOf(destNode) Then
        destNode.Nodes.Add(sourceNodeClone)
    End If
End Sub
Private Function CloneNode(ByVal sourceNode As RadTreeNode) As RadTreeNode
    Dim clonedNode As New RadTreeNode()
    clonedNode.Text = sourceNode.Text
    clonedNode.Value = sourceNode.Value
    clonedNode.ImageUrl = sourceNode.ImageUrl
    clonedNode.ExpandedImageUrl = sourceNode.ExpandedImageUrl
    Return clonedNode
End Function

See Also