BExplorer.Shell.ShellTreeViewEx.ShellTreeView_DragOver C# (CSharp) Method

		private void ShellTreeView_DragOver(object sender, DragEventArgs e) {
			var wp = new DataObject.Win32Point() { X = e.X, Y = e.Y };
			ShellView.Drag_SetEffect(e);
			var descinvalid = new DataObject.DropDescription();
			descinvalid.type = (int)DataObject.DropImageType.Invalid;
			((System.Runtime.InteropServices.ComTypes.IDataObject)e.Data).SetDropDescription(descinvalid);
			var node = this.ShellTreeView.GetNodeAt(PointToClient(new Point(e.X, e.Y)));
			if (node != null && !String.IsNullOrEmpty(node.Text) && node.Text != this._EmptyItemString) {
				User32.SendMessage(this.ShellTreeView.Handle, MSG.TVM_SETHOT, 0, node.Handle);
				var desc = new DataObject.DropDescription();
				switch (e.Effect) {
					case DragDropEffects.Copy:
						desc.type = (int)DataObject.DropImageType.Copy;
						desc.szMessage = "Copy To %1";
						break;
					case DragDropEffects.Link:
						desc.type = (int)DataObject.DropImageType.Link;
						desc.szMessage = "Create Link in %1";
						break;
					case DragDropEffects.Move:
						desc.type = (int)DataObject.DropImageType.Move;
						desc.szMessage = "Move To %1";
						break;
					case DragDropEffects.None:
						desc.type = (int)DataObject.DropImageType.None;
						desc.szMessage = "";
						break;
					default:
						desc.type = (int)DataObject.DropImageType.Invalid;
						desc.szMessage = "";
						break;
				}

				desc.szInsert = node.Text;
				((System.Runtime.InteropServices.ComTypes.IDataObject)e.Data).SetDropDescription(desc);
			}

			if (e.Data.GetDataPresent("DragImageBits"))
				DropTargetHelper.DropTarget.Create.DragOver(ref wp, (int)e.Effect);
			else
				base.OnDragOver(e);
		}