Report Control - Drag & drop with virtual records

Print Page | Close Window

Drag & drop with virtual records

Printed From: Codejock Forums
Category: Codejock Products
Forum Name: Report Control
Forum Description: Topics Related to Codejock Report Control
URL: https://forum.codejock.com/forum_posts.asp?TID=24352
Printed Date: 14 November 2026 at 11:19pm
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com

Topic: Drag & drop with virtual records

Posted By: Fredrik
Subject: Drag & drop with virtual records
Date Posted: 24 January 2023 at 3:49am

Hi all,

What's the trick handling drag & drop in a grid control having virtual records? I have added response handler for XTP_NM_GRID_BEGINDRAG but since I have virtual records I get the pointer to the same record regardless which one I drag. I could potentially use GetSelectedRows, but thought I should have the information needed in the XTP_NM_GRIDDRAGDROP structure.

Second question, is it possible to prevent the start of a drag operation when responding to XTP_NM_GRIDDRAGDROP ? I have tried setting different values on *pResult and pItemNotify->bReturnValue.

Third question: I tried to use XTP_NM_GRID_HASVALIDDROPTYPE message to change dropEffect, however, this is ignored in DROPEFFECT CXTPGridControl::OnDragOver?


		XTP_NM_GRIDDRAGDROP nmData;
		nmData.dropEffect  = dropEffect;
		nmData.pDataObject = pDataObject;
		nmData.pt		   = point;
		// R-DD <<
		nmData.dwKeyState = dwKeyState;
		// R-DD >>

		int iValid = (int)SendNotifyMessage(XTP_NM_GRID_HASVALIDDROPTYPE, (NMHDR*)&nmData);

		m_nOLEDropAbove = nmData.bAbove;

		if ((dropEffect != DROPEFFECT_NONE) // <- Shouldn't this be nmData.dropEffect?
			&& (!pDataObject || (!pDataObject->IsDataAvailable(m_cfGrid) && iValid != 1)))
			dropEffect = DROPEFFECT_NONE;

Regards,
Fredrik

-------------
Windows 11, Visual Studio 2026, Toolkit Pro 24.3.0