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...