CommonControls (Replacement of the MS common controls)

[vb6rocks]

Additionally, I was able to identify that the following line (in red) in VBCCR11 is what is causing the run-time error (Overflow):

Private Sub UserControl_OLEStartDrag(Data As DataObject, AllowedEffects As Long)
If ListViewDragIndex > 0 Then
If ListViewHandle <> 0 Then
Dim P(0 To 1) As POINTAPI, RC As RECT
GetCursorPos P(0)
ScreenToClient ListViewHandle, P(0)
SendMessage ListViewHandle, LVM_GETITEMPOSITION, ListViewDragIndex - 1, ByVal VarPtr(P(1))
SendMessage ListViewHandle, LVM_GETVIEWRECT, 0, ByVal VarPtr(RC)
ListViewDragOffsetY = (P(1).Y - P(0).Y) + RC.Top
ListViewDragOffsetX = (P(1).X - P(0).X) + RC.Left
End If
If PropOLEDragMode = vbOLEDragAutomatic Then
Dim Text As String
Text = Me.FListItemText(ListViewDragIndex, 0)
Data.SetData StrToVar(Text & vbNullChar), CF_UNICODETEXT
Data.SetData StrToVar(Text), vbCFText
AllowedEffects = vbDropEffectMove Or vbDropEffectCopy
End If
End If
RaiseEvent OLEStartDrag(Data, AllowedEffects)
If AllowedEffects = vbDropEffectNone Then ListViewDragIndex = 0
End Sub

Another difference when compared to the demo is that in our case we are doing a drag and drop on controls that are in different forms. (The demo project has both the controls in the same form.)

We are using your library extensively for Unicode support and it has been very beneficial so far.

Update: We were able to identify the root cause of the run-time error. It was caused by one of the long variables (RC.Top/ RC.Left) getting set to it's max value (2147483647) and the addition operation caused an Overflow exception.