Form1.vb

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms
Imports DevExpress.XtraTreeList
Imports DevExpress.XtraGrid
Imports DevExpress.XtraTreeList.Nodes
Imports DevExpress.XtraEditors
Imports DevExpress.Utils.DragDrop
Imports DevExpress.Utils.Behaviors

Namespace DragAndDropRows

    Public Partial Class Form1
        Inherits XtraForm

        Private gridDataSource As BindingList(Of Person) = New BindingList(Of Person)()

        Public Sub New()
            InitializeComponent()
            InitGrid()
            InitTreeList()
            InitDragDrop()
        End Sub

        Private Sub InitGrid()
            gridDataSource.Add(New Person("John", "Smith", "USA"))
            gridDataSource.Add(New Person("Michael", "Suyama", "UK"))
            gridDataSource.Add(New Person("Laura", "Callahan", "UK"))
            gridDataSource.Add(New Person("Gerard", "Blain", "France"))
            gridDataSource.Add(New Person("Sergio", "Rubini", "Italy"))
            gridDataSource.Add(New Person("Andrew", "Fuller", "USA"))
            gridControl.DataSource = gridDataSource
            ' Enable support for drag-and-drop operations within the View.
            gridView.OptionsBehavior.EditorShowMode = DevExpress.Utils.EditorShowMode.Click
        End Sub

        Private Sub InitTreeList()
            treeList.DataSource = New BindingList(Of PersonEx)()
            ' Specify the key field in the data source.
            treeList.KeyFieldName = "ID"
            ' Specify the data source field identifying the parent key field.
            treeList.ParentFieldName = "ParentID"
            ' Allow tree indents to be interpreted as parts of rows. 
            ' The TargetNode parameter of the TreeList.DragDrop event will return a proper node, when dropping over tree indents. 
            treeList.OptionsView.ShowIndentAsRowStyle = True
        End Sub

        Private Sub InitDragDrop()
            Dim behaviorManager1 As BehaviorManager = New BehaviorManager(components)
            behaviorManager1.Attach(Of DragDropBehavior)(gridView, Sub(behavior)
                behavior.Properties.AllowDrop = False
                behavior.Properties.InsertIndicatorVisible = True
                behavior.Properties.PreviewVisible = True
            End Sub)
            behaviorManager1.Attach(Of DragDropBehavior)(treeList, Sub(behavior)
                behavior.Properties.AllowDrop = True
                behavior.Properties.InsertIndicatorVisible = True
                behavior.Properties.PreviewVisible = True
                AddHandler behavior.DragOver, AddressOf OnDragOver
                AddHandler behavior.DragDrop, AddressOf OnDragDrop
            End Sub)
        End Sub

        Private Overloads Sub OnDragDrop(ByVal sender As Object, ByVal e As DragDropEventArgs)
            Dim indexes = e.GetData(Of IEnumerable(Of Integer))()
            If indexes Is Nothing Then Return
            Dim destNode = GetDestNode(e.Location)
            Dim destIndex As Integer = CalcDestNodeIndex(e, destNode)
            treeList.BeginUpdate()
            For Each _index As Integer In indexes
                Dim person = gridDataSource(_index)
                Dim parentID As Integer = -1
                If destNode IsNot Nothing Then parentID = CInt(destNode("ID"))
                Dim node As TreeListNode = treeList.AppendNode(New PersonEx(person, parentID).ToArray(), If(destIndex = -1000, destNode, Nothing))
                If destIndex > -1 Then
                    treeList.MoveNode(node, destNode.ParentNode, True, destIndex)
                    destIndex += 1
                End If

                If node.ParentNode IsNot Nothing Then node.ParentNode.Expand()
            Next

            treeList.EndUpdate()
        End Sub

        Private Function GetDestNode(ByVal hitPoint As Point) As TreeListNode
            Dim pt As Point = treeList.PointToClient(hitPoint)
            Dim ht = treeList.CalcHitInfo(pt)
            Dim destNode As TreeListNode = ht.Node
            If TypeOf destNode Is TreeListAutoFilterNode Then Return Nothing
            Return destNode
        End Function

        Private Function CalcDestNodeIndex(ByVal e As DragDropEventArgs, ByVal destNode As TreeListNode) As Integer
            If destNode Is Nothing Then Return -1
            If e.InsertType = InsertType.AsChild Then Return -1000
            Dim nodes = If(destNode.ParentNode Is Nothing, treeList.Nodes, destNode.ParentNode.Nodes)
            Dim index As Integer = nodes.IndexOf(destNode)
            If e.InsertType = InsertType.After Then Return Threading.Interlocked.Increment(index)
            Return index
        End Function

        Private Overloads Sub OnDragOver(ByVal sender As Object, ByVal e As DragOverEventArgs)
            e.Default()
            e.Action = DragDropActions.Copy
            e.Handled = True
            e.Cursor = Cursors.Default
        End Sub
    End Class
End Namespace