DragDrop Sample (VB)
This sample demonstrates copying/moving items within the same and between two tree controls using drag & drop.
The source code is located at C:\Program Files (x86)\Softelvdm\SftTree NET 2.0\Samples\VB\DragDrop.
Imports Softelvdm.SftTreeNET
Imports Softelvdm.Controls
Imports System.Reflection
Public Class Form1
Private Sub CloseButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CloseButton.Click
Close()
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
SftTree1.Initializing = True
SftTree1.AllowDrop = True
SftTree1.AutoExpandDragDrop = True
SftTree1.Columns.Count = 2
SftTree1.Headers(0, 0).Text = "Left Tree Control"
For c As Integer = 1 To SftTree1.Columns.Count - 1
SftTree1.Headers(0, c).Text = "Column " + c.ToString()
Next
For i As Integer = 0 To 100 - 1
Dim itemParent As ItemClass = SftTree1.ItemCollection.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
itemParent.RowHeader.Text = i.ToString()
i = i + 1
Dim item As ItemClass = itemParent.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
item.RowHeader.Text = i.ToString()
i = i + 1
Dim subitem As ItemClass = item.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
subitem.RowHeader.Text = i.ToString()
i = i + 1
Dim child As ItemClass = subitem.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
child.RowHeader.Text = i.ToString()
i = i + 1
child = item.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
child.RowHeader.Text = i.ToString()
Next
SftTree1.Columns.MakeOptimal(0, False)
SftTree1.RowHeaders.MakeOptimal(0, False)
SftTree1.RecalcHorizontalExtent()
SftTree1.Initializing = False
SftTree2.Initializing = True
SftTree2.AllowDrop = True
SftTree2.AutoExpandDragDrop = True
SftTree2.Columns.Count = 3
SftTree2.RowHeaders.Width = 0
SftTree2.Headers(0, 0).Text = "Right Tree Control"
For c As Integer = 1 To SftTree2.Columns.Count - 1
SftTree2.Headers(0, c).Text = "Column " + c.ToString()
Next
For i As Integer = 0 To 100 - 1
Dim itemParent As ItemClass = SftTree2.ItemCollection.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
itemParent.RowHeader.Text = i.ToString()
i = i + 1
Dim item As ItemClass = itemParent.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
item.RowHeader.Text = i.ToString()
i = i + 1
Dim subitem As ItemClass = item.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
subitem.RowHeader.Text = i.ToString()
i = i + 1
Dim child As ItemClass = subitem.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
child.RowHeader.Text = i.ToString()
i = i + 1
child = item.Add(New String() {"Item " + i.ToString(), "Cell 1 in Item " + i.ToString(), "Cell 2 in Item " + i.ToString()})
child.RowHeader.Text = i.ToString()
Next
SftTree2.Columns.MakeOptimal(0, False)
SftTree2.RecalcHorizontalExtent()
SftTree2.Initializing = False
End Sub
Private Sub sftTree1_DragDetected(ByVal sender As System.Object, ByVal e As Softelvdm.SftTreeNET.DragDetectedEventArgs) Handles SftTree1.DragDetected
Debug.Write("sftTree1_DragDetected ")
DumpValues(e)
' get the current item
If e.Item Is Nothing Then Return
Dim item As ItemClass = e.Item
' don't drag headers, footers
If item.UsageLocation <> UsageLocationEnum.items Then Return
' start dragging the item
SftTree1.DoDragDrop(e.Item, DragDropEffects.Copy Or DragDropEffects.Move)
End Sub
Private Sub sftTree1_DragOver(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles SftTree1.DragOver
Debug.WriteLine("sftTree1_DragOver ")
e.Effect = DragDropEffects.None
If Not SftTree1.DropTarget Is Nothing And e.Data.GetDataPresent(GetType(ItemClass)) Then
' Copy or move based on control key
If ((Control.ModifierKeys And Keys.Control) <> 0) Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.Move
End If
End If
End Sub
Private Sub sftTree1_DragDrop(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles SftTree1.DragDrop
Debug.Write("sftTree1_DragDrop ")
DumpValues(e)
If Not SftTree1.DropTarget Is Nothing And e.Data.GetDataPresent(GetType(ItemClass)) Then
Dim originalItem As ItemClass = e.Data.GetData(GetType(ItemClass))
Dim targetItem As ItemClass = SftTree1.DropTarget
Dim newItem As ItemClass = Nothing
If e.Effect = DragDropEffects.Move Then
Try
newItem = originalItem.Move(targetItem, MoveStyleEnum.TargetAsParentInsertFirst)
Catch exc As Exception
MessageBox.Show(exc.Message)
End Try
Else
Try
newItem = originalItem.Copy(targetItem, CopyStyleEnum.TargetAsParentInsertFirst, True)
Catch exc As Exception
MessageBox.Show(exc.Message)
End Try
End If
If Not newItem Is Nothing Then
SftTree1.Columns.MakeOptimal(0, False)
newItem.ScrollIntoView()
End If
End If
End Sub
Private Sub sftTree2_DragDetected(ByVal sender As System.Object, ByVal e As Softelvdm.SftTreeNET.DragDetectedEventArgs) Handles SftTree2.DragDetected
Debug.Write("sftTree2_DragDetected ")
DumpValues(e)
' get the current item
If e.Item Is Nothing Then Return
Dim item As ItemClass = e.Item
' don't drag headers, footers
If item.UsageLocation <> UsageLocationEnum.items Then Return
' start dragging the item
SftTree2.DoDragDrop(e.Item, DragDropEffects.Copy Or DragDropEffects.Move)
End Sub
Private Sub sftTree2_DragOver(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles SftTree2.DragOver
Debug.WriteLine("sftTree2_DragOver ")
e.Effect = DragDropEffects.None
If Not SftTree2.DropTarget Is Nothing And e.Data.GetDataPresent(GetType(ItemClass)) Then
' Copy or move based on control key
If ((Control.ModifierKeys And Keys.Control) <> 0) Then
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.Move
End If
End If
End Sub
Private Sub sftTree2_DragDrop(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles SftTree2.DragDrop
Debug.Write("sftTree2_DragDrop ")
DumpValues(e)
If Not SftTree2.DropTarget Is Nothing And e.Data.GetDataPresent(GetType(ItemClass)) Then
Dim originalItem As ItemClass = e.Data.GetData(GetType(ItemClass))
Dim targetItem As ItemClass = SftTree2.DropTarget
Dim newItem As ItemClass = Nothing
If e.Effect = DragDropEffects.Move Then
Try
newItem = originalItem.Move(targetItem, MoveStyleEnum.TargetAsParentInsertFirst)
Catch exc As Exception
MessageBox.Show(exc.Message)
End Try
Else
Try
newItem = originalItem.Copy(targetItem, CopyStyleEnum.TargetAsParentInsertFirst, True)
Catch exc As Exception
MessageBox.Show(exc.Message)
End Try
End If
If Not newItem Is Nothing Then
SftTree2.Columns.MakeOptimal(0, False)
newItem.ScrollIntoView()
End If
End If
End Sub
' This is a small helper routine to show all properties and fields of an object
Private Sub DumpValues(ByVal o As Object)
Dim api() As PropertyInfo = o.GetType().GetProperties()
For Each pi As PropertyInfo In api
Dim ov = pi.GetValue(o, New Object() )
Dim s As String = " " & pi.Name
If Not ov Is Nothing Then s = s + " " + ov.ToString()
Debug.Write(s)
Next
Dim afi() As FieldInfo = o.GetType().GetFields()
For Each fi As FieldInfo In afi
Dim ov = fi.GetValue(o)
Dim s As String = " " & fi.Name
If Not ov Is Nothing Then s = s + " " + ov.ToString()
Debug.Write(s)
Next
Debug.WriteLine("")
End Sub
End Class
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