RadTreeview dragdrop event not get triggered

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
   RadTreeView1.AllowDragDrop = True      
   RadTreeView1.AllowDrop = True
 ' Add event handlers for drag and drop events
   AddHandler RadTreeView1.DragEnter, AddressOf RadTreeView1_DragEnter
   AddHandler RadTreeView1.DragDrop, AddressOf RadTreeView1_DragDrop
End Sub

Private Sub RadTreeView1_DragEnter(sender As Object, e As DragEventArgs) Handles RadTreeView1.DragEnter
    ' Check if the data being dragged is a RadTreeNode
    If e.Data.GetDataPresent(GetType(RadTreeNode)) Then
        e.Effect = DragDropEffects.Move
    Else
        e.Effect = DragDropEffects.None
    End If
End Sub

Private Sub RadTreeView1_DragDrop(sender As Object, e As DragEventArgs) Handles RadTreeView1.DragDrop
    ' Check if the data being dragged is a RadTreeNode
    If e.Data.GetDataPresent(GetType(RadTreeNode)) Then
        ' Get the dragged node
        Dim draggedNode As RadTreeNode = CType(e.Data.GetData(GetType(RadTreeNode)), RadTreeNode)

        ' Get the target node
        Dim targetNode As RadTreeNode = RadTreeView1.GetNodeAt(RadTreeView1.PointToClient(New Point(e.X, e.Y)))

        ' Get the full path of the dragged node
        Dim draggedNodePath As String = draggedNode.FullPath

        ' Get the full path of the target node
        Dim targetNodePath As String = targetNode.FullPath

        ' Do something with the full paths
        MessageBox.Show("Dragged Node Path: " & draggedNodePath & vbCrLf & "Target Node Path: " & targetNodePath)
    End If
End Sub