继承IDropSource和IDataObject的文件拖拽，为何无法成功将文件发送到指定窗口？？

gfvera 2016-03-16 05:17:06

在 DoDragDrop中返回值为DRAGDROP_S_DROP，但是却没有移动文件？？？我的代码哪里写错了？？？？

下面这个是我在鼠标移动时的代码。。。。。

其中CIDropSource和CIDataObject的类在这里下载代码。。。Download source - 3.8 Kb
http://www.codeproject.com/Articles/12342/Drag-and-Drop-Listbox-Items-using-OLE



bool CImageItem::DragDropTo2(QString path, int DropStyle)

{

    OleInitialize(NULL);    // needed for Drag and Drop

      

    CIDropSource* src = new CIDropSource;

    if (src == nullptr) return false;

     

    CIDataObject* obje = new CIDataObject(src);

    if (obje == nullptr)

    {

        OleUninitialize();

        delete src;

        return false;

    }

     

    FORMATETC fmtetc = { CF_TEXT, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };

    STGMEDIUM stgmed = { TYMED_HGLOBAL, { 0 }, 0 };

    STGMEDIUM dest = { TYMED_HGLOBAL, { 0 }, 0 };



    stgmed.hGlobal = GlobalAlloc(GMEM_MOVEABLE, strlen(path.toLatin1().data()) + 1);

    char *pChar = (char *)GlobalLock(stgmed.hGlobal);

    strcpy(pChar, path.toLatin1().data());

    GlobalUnlock(stgmed.hGlobal);

      

    obje->CopyMedium(&dest, &stgmed, &fmtetc);

         

    DWORD        dwEffect;

    DWORD        dwResult;  

    dwResult = DoDragDrop(obje, src, DROPEFFECT_COPY | DROPEFFECT_MOVE, &dwEffect); 

    if (dwResult == DRAGDROP_S_DROP)

    {

      //通过调试输出，这里是成功的。

        OutputDebugString(L"[3dh] ok");

        if (dwEffect & DROPEFFECT_MOVE)

        {

             //这里并没有过来。。。。

            OutputDebugString(L"[3dh] ok2");

        }

    } 

    else if (dwResult == DRAGDROP_S_CANCEL)

    {

        OutputDebugString(L"[3dh] no");

    } 



      //正常来说这里应该有上面两个指针的Release()。但是如果Release会崩掉。。。这是问题2.。。。

      if (obje != null)

         obje->Release()　／／崩溃。



      if (src  != null)

          src->.RElease(); 

    

      

    OleUninitialize(); 

    return true;

}

...全文

332 9 打赏收藏转发到动态举报

写回复

用AI写文章

9 条回复

切换为时间正序

请发表友善的回复…

发表回复

dustpg 2016-03-17

打赏
举报

移动文件，我看错了么, CF是CF_TEXT, 怎么移动文件

赵4老师 2016-03-17

打赏
举报

引用 5 楼 crow_sky 的回复:

[quote=引用 4 楼 dustpg 的回复:] 移动文件，我看错了么, CF是CF_TEXT, 怎么移动文件

我对着不熟。。。。请问应该要修改成什么样的。。。[/quote] 仅供参考： File: "C:\Program Files\Microsoft Visual Studio\VC98\Include\WINUSER.H"

    2097: /*
    2098:  * Predefined Clipboard Formats
    2099:  */
    2100: #define CF_TEXT             1
    2101: #define CF_BITMAP           2
    2102: #define CF_METAFILEPICT     3
    2103: #define CF_SYLK             4
    2104: #define CF_DIF              5
    2105: #define CF_TIFF             6
    2106: #define CF_OEMTEXT          7
    2107: #define CF_DIB              8
    2108: #define CF_PALETTE          9
    2109: #define CF_PENDATA          10
    2110: #define CF_RIFF             11
    2111: #define CF_WAVE             12
    2112: #define CF_UNICODETEXT      13
    2113: #define CF_ENHMETAFILE      14
    2114: #if(WINVER >= 0x0400)
    2115: #define CF_HDROP            15
    2116: #define CF_LOCALE           16
    2117: #define CF_MAX              17
    2118: #endif /* WINVER >= 0x0400 */

gfvera 2016-03-17

打赏
举报

引用 4 楼 dustpg 的回复:

移动文件，我看错了么, CF是CF_TEXT, 怎么移动文件

我对着不熟。。。。请问应该要修改成什么样的。。。

gfvera 2016-03-17

打赏
举报

引用 7 楼 schlafenhamster 的回复:

干嘛要自己实现？

因为并不是在MFC下使用。而是在QT。。。QT中拖拽就算创建隐藏的MFCDLG也没用。。只能自己实现。。

void_main_void 2016-03-17

打赏
举报

http://blog.csdn.net/qazwsxwtc/article/details/44279529 封装的类。调用


IDropSource *pDropSource;
    IDataObject *pDataObject;
      
    FORMATETC fmtetc = { CF_HDROP, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
    STGMEDIUM stgmed = { TYMED_HGLOBAL, { 0 }, 0 };
      
    stgmed.hGlobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_ZEROINIT | GMEM_DDESHARE, MAX_PATH * 2);
    
    LPDROPFILES pDropFiles = (LPDROPFILES)::GlobalLock(stgmed.hGlobal);
    pDropFiles->pFiles = sizeof(DROPFILES);
    pDropFiles->fWide = TRUE;
    LPBYTE pData = (LPBYTE)pDropFiles + sizeof(DROPFILES); 
    memcpy(pData, path, sizeof(WCHAR)*wcslen(path));
    ::GlobalUnlock(stgmed.hGlobal);

    if (CDropSource::CreateDropSource(&pDropSource) != S_OK) return false;

    if (CDataObject::CreateDataObject(&fmtetc, &stgmed, 1, &pDataObject) != S_OK)
    {
        delete pDropSource;
        return false;
    }
         
    DWORD        dwEffect;
    DWORD        dwResult;  
    dwResult = DoDragDrop(pDataObject, pDropSource, DROPEFFECT_COPY, &dwEffect);
      
    pDataObject->Release();
    pDropSource->Release();

schlafenhamster 2016-03-17

打赏
举报

干嘛要自己实现？


void CHMI_manView::OnBegindrag(NMHDR* pNMHDR, LRESULT* pResult) 
{
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
	// TODO: Add your control notification handler code here
// check select
	CMainFrame*  pMain=(CMainFrame*)AfxGetMainWnd();
	CListCtrl&   RightCtrl=this->GetListCtrl();
// check selection
	if(!pMain->CheckCurrentSelection(FALSE,TRUE,TRUE))//mul;no ':' no dir
	{//only multi files ;no drive;no dir
		*pResult = 0;
		return;
	}
	char Selection[40*MaxSelectNum];
//	get selection
	if(!pMain->GetCurrentSelection(Selection,FALSE))
	{// as src
		*pResult = 0;
		return;
	}
// selected list-items
	int iItem=m_pIndx[0];
// 	
	HGLOBAL hGlobal=GlobalAlloc(GMEM_SHARE,strlen(Selection)+1);
	LPSTR pszGlobal=(LPSTR)GlobalLock(hGlobal);
	ASSERT(pszGlobal);
	strcpy(pszGlobal,Selection);
	GlobalUnlock(hGlobal);
	COleDataSource* pSource=new COleDataSource();
	pSource->CacheGlobalData(CF_TEXT,hGlobal);
// save for checking
	SetDragItem(iItem);
// drag image
	if(pMain->m_pDragImage) delete pMain->m_pDragImage;
// create only 1 ??
	CPoint pthot(0,0);
	pMain->m_pDragImage=RightCtrl.CreateDragImage(iItem,&pthot);
// pos of item
	CRect rc;
	RightCtrl.GetItemRect(iItem,&rc,LVIR_BOUNDS);
// pos of cursor
	CPoint pt,hpt;
	GetCursorPos(&pt);
	RightCtrl.ScreenToClient(&pt);// pt is in DeskTop
// hotpoint
	hpt.x=pt.x-rc.left+12;
	hpt.y=pt.y-rc.top;
// Start dragging the image.
	pMain->m_pDragImage->BeginDrag(0,hpt);
// do dragdrop
	DROPEFFECT de;
	de=pSource->DoDragDrop(DROPEFFECT_COPY | DROPEFFECT_MOVE );//| DROPEFFECT_SCROLL);
// delete as many items as selected in list 
	if(de==DROPEFFECT_MOVE)
	{
		ListReMoveItems();
	}
// reset all
	SetDragItem(-1);
	pMain->m_pDragImage->EndDrag();
// 
	if(pSource) delete pSource;
	*pResult = 0;
}

注意 COleDataSource* pSource=new COleDataSource();

gfvera 2016-03-16