• exAutoDragPosition... (the item can be dragged from a position to another, but not outside of its group)
• exAutoDragPositionKeepIndent... (the item can be dragged to any position or to any parent, while the dragging object keeps its indentation)
• exAutoDragPositionAny... (the item can be dragged to any position or to any parent, with no restriction)

You can use the AllowAutoDrag event to cancel or continue drag and drop operation using the AutoDrag property.

The following screen shot shows the NewParent, InsertA and InsertB parameters, when "Task 2" is dragging to a new position:

• NewParent is "Group 1"
• InsertA is "Task 1"
• InsertB is "Task 3"

• NewParent is "Task 1"
• InsertA is 0
• InsertB is 0

• NewParent is 0
• InsertA is "Group 2"
• InsertB is 0

private void AllowAutoDrag(object sender,int   Item,int   NewParent,int   InsertA,int   InsertB,ref bool   Cancel)
{
}

Private Sub AllowAutoDrag(ByVal sender As System.Object,ByVal Item As Integer,ByVal NewParent As Integer,ByVal InsertA As Integer,ByVal InsertB As Integer,ByRef Cancel As Boolean) Handles AllowAutoDrag
End Sub

private void AllowAutoDrag(object sender, AxEXTREELib._ITreeEvents_AllowAutoDragEvent e)
{
}

void OnAllowAutoDrag(long   Item,long   NewParent,long   InsertA,long   InsertB,BOOL FAR*   Cancel)
{
}

void __fastcall AllowAutoDrag(TObject *Sender,Extreelib_tlb::HITEM   Item,Extreelib_tlb::HITEM   NewParent,Extreelib_tlb::HITEM   InsertA,Extreelib_tlb::HITEM   InsertB,VARIANT_BOOL *   Cancel)
{
}

procedure AllowAutoDrag(ASender: TObject; Item : HITEM;NewParent : HITEM;InsertA : HITEM;InsertB : HITEM;var Cancel : WordBool);
begin
end;

procedure AllowAutoDrag(sender: System.Object; e: AxEXTREELib._ITreeEvents_AllowAutoDragEvent);
begin
end;

begin event AllowAutoDrag(long  Item,long  NewParent,long  InsertA,long  InsertB,boolean  Cancel)

end event AllowAutoDrag

Private Sub AllowAutoDrag(ByVal sender As System.Object, ByVal e As AxEXTREELib._ITreeEvents_AllowAutoDragEvent) Handles AllowAutoDrag
End Sub

Private Sub AllowAutoDrag(ByVal Item As EXTREELibCtl.HITEM,ByVal NewParent As EXTREELibCtl.HITEM,ByVal InsertA As EXTREELibCtl.HITEM,ByVal InsertB As EXTREELibCtl.HITEM,Cancel As Boolean)
End Sub

Private Sub AllowAutoDrag(ByVal Item As Long,ByVal NewParent As Long,ByVal InsertA As Long,ByVal InsertB As Long,Cancel As Boolean)
End Sub

LPARAMETERS Item,NewParent,InsertA,InsertB,Cancel

PROCEDURE OnAllowAutoDrag(oTree,Item,NewParent,InsertA,InsertB,Cancel)

RETURN

<SCRIPT EVENT="AllowAutoDrag(Item,NewParent,InsertA,InsertB,Cancel)" LANGUAGE="JScript">
</SCRIPT>

<SCRIPT LANGUAGE="VBScript">
Function AllowAutoDrag(Item,NewParent,InsertA,InsertB,Cancel)
End Function
</SCRIPT>

Procedure OnComAllowAutoDrag HITEM   llItem HITEM   llNewParent HITEM   llInsertA HITEM   llInsertB Boolean   llCancel
	Forward Send OnComAllowAutoDrag llItem llNewParent llInsertA llInsertB llCancel
End_Procedure

METHOD OCX_AllowAutoDrag(Item,NewParent,InsertA,InsertB,Cancel) CLASS MainDialog
RETURN NIL

void onEvent_AllowAutoDrag(int   _Item,int   _NewParent,int   _InsertA,int   _InsertB,COMVariant /*bool*/   _Cancel)
{
}

function AllowAutoDrag as v (Item  as  OLE::Exontrol.Tree.1::HITEM,NewParent  as  OLE::Exontrol.Tree.1::HITEM,InsertA  as  OLE::Exontrol.Tree.1::HITEM,InsertB  as  OLE::Exontrol.Tree.1::HITEM,Cancel  as  L)
end function

function nativeObject_AllowAutoDrag(Item,NewParent,InsertA,InsertB,Cancel)
return

The AllowDragDrop event triggers contiguously while the user drags / hovers the focus/selection of items over the control. The GetAsyncKeyState API method can be used to detect whether the mouse button has been released, and so the drop action occurs. 

The following VB sample displays "Drag" while user dragging the items, and displays "Drop", when drop operation starts.

Private Sub Tree1_AllowAutoDrag(ByVal Item As EXTREELibCtl.HITEM, ByVal NewParent As EXTREELibCtl.HITEM, ByVal InsertA As EXTREELibCtl.HITEM, ByVal InsertB As EXTREELibCtl.HITEM, Cancel As Boolean)
    With Tree1
        Debug.Print "Drag"
        If (GetAsyncKeyState(VK_LBUTTON) = 0) Then
            Debug.Print "Drop"
        End If
    End With
End Sub

where declarations for GetAsyncKeyState API used is:

Private Const VK_LBUTTON = &H1
Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer

Once you run the code, you will notice that the AllowAutoDrag event "Drop" may be fired multiple times, so we suggest to postpone any of your actions ( like displaying a message box ), by posting a window message or use a timer event, to let the control handles / completes the event as in the following sample:

Private Sub Tree1_AllowAutoDrag(ByVal Item As EXTREELibCtl.HITEM, ByVal NewParent As EXTREELibCtl.HITEM, ByVal InsertA As EXTREELibCtl.HITEM, ByVal InsertB As EXTREELibCtl.HITEM, Cancel As Boolean)
    With Tree1
        Debug.Print "Drag"
        If (GetAsyncKeyState(VK_LBUTTON) = 0) Then
            mctlTimerDrop.Enabled = True
        End If
    End With
End Sub

where mctlTimerDrop is defined as follows:

Dim WithEvents mctlTimerDrop As VB.Timer

Private Sub mctlTimerDrop_Timer()
    mctlTimerDrop.Enabled = False
    MsgBox "Drop."
End Sub


Private Sub Form_Load()
    Set mctlTimerDrop = Me.Controls.Add("VB.Timer", "DropTimer1")
    With mctlTimerDrop
        .Enabled = False
        .Interval = 100
    End With
End Sub