Something like this maybe... string errorMessage = new System.ComponentModel.Win32Exception(System.Runtime.InteropServices.Marshal.GetLastWin32Error()).Message; Or maybe p/invoke the Win32 FormatMessage() API. Mark Mark Salsbery Microsoft MVP - Visual C++ :java:

System.Windows.Forms.SystemInformation.VerticalScrollBarWidth; led mike

Thanks Luc, Setting EndCap and StartCap to LineCap.Square solved it. Kees

Luc Pattyn wrote: Yes, I know what they do, but why choose names that are counterintuitive, i.e. don't match real-world terms. They match the real-world items if you think of them from a certain point of view. Computerised real-world concepts often mimic only some aspects but not all. If you take radio buttons for example, they pop out just like buttons on a real radio, but you can't turn them to change the preset frequency. Luc Pattyn wrote: I would prefer a Map for a .NET Dictionary A map to me is something that describes two dimensional geographical data, so that would be even more confusing... Luc Pattyn wrote: and a SortedMap for a .NET SortedList (it isn't a sorted List, in .NET terms it is a sorted dictionary). The internal storage for a SortedList is a pair of arrays, so it actually is a sorted list. :) Despite everything, the person most likely to be fooling you next is yourself.

Thanks for your reply. Meanwhile I've come a lot further. The problem was that methods SetData and GetData where not implemented. Therefore I created a new DataObject class which re-implements these methods. This is the code I have so far which is working but needs some adjustments here and there. Also I'm not sure whether all allocated objects are released correctly. Regards, Kees public partial class CustomControl1 : Control { DragDropHelper Helper; public CustomControl1() { InitializeComponent(); this.AllowDrop = true; } protected override void OnPaint(PaintEventArgs pe) { Brush B = new SolidBrush(Color.White); pe.Graphics.FillRectangle(B, pe.ClipRectangle); } protected override void OnMouseDown(MouseEventArgs e) { DataFormats.Format ganttbarFormat = DataFormats.GetFormat("Ganttbar"); object ganttbar = new object(); DataObject dragObject = new DataObjectEx(ganttbarFormat.Name, ganttbar); DoDragDrop(dragObject, DragDropEffects.All); } private void UpdateDragImage(System.Runtime.InteropServices.ComTypes.IDataObject dragObject) { if (Helper == null) { Helper = new DragDropHelper(); } IDragSourceHelper Drag = (IDragSourceHelper)Helper; SHDRAGIMAGE tt = new SHDRAGIMAGE(); Bitmap img = new Bitmap(@"C:\Temp\DragImage.bmp"); tt.ptOffset.x = 0; tt.ptOffset.y = 0; tt.sizeDragImage.x = img.Width; tt.sizeDragImage.y = img.Height; tt.hbmpDragImage = img.GetHbitmap(); tt.crColorKey = 0; Drag.InitializeFromBitmap(ref tt, dragObject); } protected override void OnDragOver(DragEventArgs drgevent) { IDropTargetHelper H = (IDropTargetHelper)Helper; POINT p = new POINT(); p.x = drgevent.X; p.y = drgevent.Y; H.DragOver(ref p, DragDropEffects.Copy); drgevent.Effect = DragDropEffects.Copy; } protected override void OnDragDrop(DragEventArgs drgevent) { System.Runtime.InteropServices.ComTypes.IDataObject dragObject = (System.Runtime.InteropServices.ComTypes.IDataObject)drgevent.Data; IDropTargetHelper H = (IDropTargetHelper)Helper; POINT p = new POINT(); p.x = drgevent.X; p.y = drgevent.Y; H.Drop(dragObject, ref p, DragDropEffects.Copy); base.OnDragDrop(drgevent); } protected override void OnDragEnter(DragEventArgs drgevent)

Thanks for your support.

Reflector? I never used it, where can I find this tool? Kees

Thanks for your reply, your information is very clear.