Re: Problem with drag&drop into a control

i use an Old inherit from COleDataSource, and register format
UINT g_uCustomClipbrdFormat = RegisterClipboardFormat(CFSTR_FILECONTENTS);

// --------------------------------------------------
// my code starts here
//COleDataSource datasrc;
 //for dragging image
 COleDataSourceEx datasrc;

 HGLOBAL hgDrop;
 DROPFILES* pDrop;
 CStringList lsDraggedFiles;
 POSITION pos;
 int nSelItem;
 CString sFile;
 UINT uBuffSize = 0;
 TCHAR* pszBuff;
 FORMATETC etc = { CF_HDROP, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
 //FORMATETC etc = { g_uCustomClipbrdFormat, NULL, DVASPECT_CONTENT, -1,
TYMED_HGLOBAL };

 *pResult = 0; // return value ignored

 // For every selected item in the list, put the filename into
lsDraggedFiles.
 pos = this->GetFirstSelectedItemPosition();

 while(NULL != pos)
 {
  nSelItem = this->GetNextSelectedItem(pos);
  sFile = this->GetFileNameFromIdx(nSelItem);

  lsDraggedFiles.AddTail(sFile);

  // Calculate the # of chars required to hold this string.
  uBuffSize += lstrlen(sFile) + 1;
 }

 // Add 1 extra for the final null char, and the size of the DROPFILES
struct.
 uBuffSize = sizeof(DROPFILES) + sizeof(TCHAR) * (uBuffSize + 1);

 // Allocate memory from the heap for the DROPFILES struct.
 hgDrop = GlobalAlloc(GHND | GMEM_SHARE, uBuffSize);
 //hgDrop = GlobalAlloc(GMEM_MOVEABLE|GMEM_DDESHARE|GMEM_ZEROINIT,
uBuffSize);

 if(NULL == hgDrop)
  return;

 pDrop = (DROPFILES*) GlobalLock(hgDrop);

 if(NULL == pDrop)
 {
  GlobalFree(hgDrop);
  return;
 }

 // Fill in the DROPFILES struct.
 pDrop->pFiles = sizeof(DROPFILES);

#ifdef _UNICODE
 // If we're compiling for Unicode, set the Unicode flag in the struct to
 // indicate it contains Unicode strings.
 pDrop->fWide = TRUE;
#endif

 // Copy all the filenames into memory after the end of the DROPFILES
struct.
 pos = lsDraggedFiles.GetHeadPosition();
 pszBuff = (TCHAR*) (LPBYTE(pDrop) + sizeof(DROPFILES));

 while(NULL != pos)
 {
  lstrcpy(pszBuff, (LPCTSTR) lsDraggedFiles.GetNext(pos));
  pszBuff = 1 + _tcschr(pszBuff, '\0');
 }

 GlobalUnlock(hgDrop);

 // Put the data in the data source.
 //datasrc.CacheGlobalData(CF_HDROP, hgDrop, &etc);
 datasrc.CacheGlobalData(g_uCustomClipbrdFormat, hgDrop, &etc);

 // Add in our own custom data, so we know that the drag originated from our
 // window. CMyDropTarget::DragEnter() checks for this custom format, and
 // doesn't allow the drop if it's present. This is how we prevent the user
 // from dragging and then dropping in our own window.
 // The data will just be a dummy bool.
 HGLOBAL hgBool;

 hgBool = GlobalAlloc(GHND | GMEM_SHARE, sizeof(bool));

 if(NULL == hgBool)
 {
  GlobalFree(hgDrop);
  return;
 }

 // Put the data in the data source.
 etc.cfFormat = g_uCustomClipbrdFormat;
 datasrc.CacheGlobalData(g_uCustomClipbrdFormat, hgBool, &etc);

 //PRAPARE IMAGE FOR DRAGGING
 if (m_UseDragHelper) {
  m_pDragHelper->InitializeFromWindow(this->m_hWnd,
&pNMLV->ptAction,(IDataObject*)datasrc.GetInterface(&IID_IDataObject));
  this->SetPivotItem(&pNMLV->ptAction);
 }

 // Start the drag 'n' drop!
 DROPEFFECT dwEffect = datasrc.DoDragDrop(DROPEFFECT_COPY | DROPEFFECT_MOVE
| DROPEFFECT_LINK);

"David Ching" <dc@remove-this.dcsoft.com> wrote in message
news:93037955-F988-4388-BA72-9A6DAAD23C35@microsoft.com...