SHBrowseForFolder BFFM_IUNKNOWN 怎么用？

[HelloDan]

我想在SHBrowseForFolder中过滤掉CD/DVD，但不知要怎样做，因为我对com熟悉，有没有人可以提示一下的？谢谢！


Custom Filtering

As of Windows XP, SHBrowseForFolder supports custom filtering on the contents of the dialog box. To create a custom filter, follow these steps.

1. Set the BIF_NEWDIALOGSTYLE flag in the ulFlags member of the BROWSEINFO structure pointed to by the lpbi parameter.
2. Specify a callback function in the lpfn member of that same BROWSEINFO structure.
3. Code the callback function to receive the BFFM_INITIALIZED and BFFM_IUNKNOWN messages. On receipt of the BFFM_IUNKNOWN message, the callback function's lParam parameter contains a pointer to the dialog box's implementation of IUnknown. Call QueryInterface on that IUnknown to obtain a pointer to an instance of IFolderFilterSite.
4. Create an object that implements IFolderFilter.
5. Call IFolderFilterSite::SetFilter, passing to it a pointer to your IFolderFilter. IFolderFilter methods can then be used to include and exclude items from the tree.
6. Once the filter is created, the IFolderFilterSite interface is no longer needed. Call IFolderFilterSite::Release if you have no further use for it.

[liumenghappy]

不懂，帮你顶起

[HelloDan]

[Quote=引用 1 楼 liumenghappy 的回复:]
不懂，帮你顶起
[/Quote]

谢谢！

[jeff_5388]

class CFolderFilter : public IFolderFilter
{

...


};

int CALLBACK BrowseCallbackProc(HWND hwnd, UINT uMsg, LPARAM lParam, LPARAM lpData)
｛
if (uMsg == BFFM_IUNKNOWN) {
IUnknown * lpUnk = (IUnknown*)lParam;
CComQIPtr<IFolderFilterSite> spSite(lpUnk);
CFolderFilter * lpFilter = new CFolderFilter;
spSite->SetFilter(lpFilter);
}

｝

BROWSEINFO bi = { 0 };
...
bi.lpfn = BrowseCallbackProc;

[HelloDan]

//我这样做了。。。

// The following code to get a folder path which you //select.
BOOL ShellGetOutPath(HANDLE hDlg, LPTSTR lpszRoot, LPTSTR lpszPath, LPCTSTR lpszDesc/* = 0*/)
{
	BOOL bRet;
	//TCHAR szPath[MAX_PATH];
	LPITEMIDLIST lpil;
	//HGLOBAL hgMem;
	
	// the following segment define and initialize the BROWSEINFO, prepareing for the SHBrowseForFolder API
	BROWSEINFO bi;
	bi.hwndOwner=(HWND) hDlg;
	IShellFolder *ppshf;
	SHGetDesktopFolder(&ppshf);
	if(!ppshf)
		return FALSE;
	LPITEMIDLIST pidlRoot = NULL;
	ppshf->ParseDisplayName((HWND)hDlg, NULL, lpszRoot, NULL, &pidlRoot, NULL);
	if(!pidlRoot)
		return FALSE;
	bi.pidlRoot = pidlRoot;
	bi.pszDisplayName = lpszPath;//szPath;
	//strMsg.LoadString(IDS_STR_FOLDER_OUTPUT);
	bi.lpszTitle = lpszDesc;
	bi.ulFlags = /*BIF_DONTGOBELOWDOMAIN |*/BIF_RETURNONLYFSDIRS | BIF_NEWDIALOGSTYLE ;
	bi.lpfn =  BFFCALLBACK(BrowseCallbackProcInit);
	bi.lParam = (LPARAM)lpszPath;
	lpil = SHBrowseForFolder(&bi);
	if(lpil == NULL)
		return FALSE;
	bRet = SHGetPathFromIDList(lpil, lpszPath);
	CoTaskMemFree(lpil);
	//CString strPath = lpszPath;
	TCHAR szDrive[_MAX_DRIVE];
	_tsplitpath(lpszPath, szDrive, NULL, NULL, NULL);
	return bRet;
}


// the callback function for the BROWSEINFO, to implement your own function
// here I try to do that:
//  1, when the user slelect CD/DVD drives, the OK and Make New Folder button
//     will be disable.
//  2, Change the title of the dialogbox.
int CALLBACK BrowseCallbackProcInit(HWND hwnd, UINT uMsg, LPARAM lParam, LPARAM lpData)
{
	TCHAR szPath[MAX_PATH];
	//	TCHAR szTargetPath[MAX_PATH];
	TCHAR szDrive[MAX_PATH], szDir[MAX_PATH], szFile[MAX_PATH], szExt[MAX_PATH];
	LPCITEMIDLIST pidl;
	//	WIN32_FIND_DATA FileData; 
	//	HANDLE hSearch; 
    static HWND hMakeNewFolder=NULL;
    
	TCHAR szWindosText[MAX_PATH+1];
	switch(uMsg)
	{
	case BFFM_SELCHANGED:
		{
			pidl = LPCITEMIDLIST(lParam);
			SHGetPathFromIDList(pidl, szPath);			
			if (szPath[0] == '\0')
				SendMessage(hwnd, BFFM_ENABLEOK, lParam, 0);
			_tsplitpath(szPath, szDrive, szDir, szFile, szExt);		
	        TCHAR szRoot[MAX_PATH+1];
			lstrcpyn(szRoot,szPath, MAX_PATH);
			::PathStripToRoot(szRoot);
			// disable when select CD/DVD drive, otherwise enables
			if(GetDriveType(szRoot)==DRIVE_CDROM)
			{
				HWND btnHwnd=GetDlgItem(hwnd,IDOK);
				::EnableWindow( btnHwnd, FALSE);
				if(hMakeNewFolder)
					::EnableWindow(hMakeNewFolder,FALSE);
				//SendMessage(hwnd,BFFM_SETSELECTION ,TRUE ,(LPARAM)(_T("C:\\")));
			}
			else
			{
			  HWND btnHwnd=GetDlgItem(hwnd,IDOK);
			 ::EnableWindow( btnHwnd, TRUE);
			 if(hMakeNewFolder)
				 ::EnableWindow(hMakeNewFolder,TRUE);
			}
	 
		}
		break;
	case BFFM_INITIALIZED:
		{
			SendMessage(hwnd, BFFM_SETSELECTION, TRUE, (LPARAM)(LPCTSTR)lpData);
			//if (szLastPath[0] == '\0')
			//	SendMessage(hwnd, BFFM_ENABLEOK, lParam, 0);
			//Change the caption of the Browse for Folder caption
			CString szCaption((LPCTSTR)lpData);
			if(szCaption.GetLength()>2)
			{
				szCaption.LoadString(IDS_SAVE_AGENT_INSTALLER);
				SetWindowText(hwnd,szCaption);
			}
			HWND   hChild=GetWindow(hwnd, GW_CHILD);
			//Get the tree view handle
			//while(hChild)
			//{
			//	TCHAR szClass[256];
			//	GetClassName(hChild, szClass, 255);
			//	// 
			//	if (strcmp(szClass, _T("SHBrowseForFolder ShellNameSpace Control")) == 0)
			//	{
   //                     hTree=hChild;
			//			break;
			//	}
			//	hChild = GetNextWindow(hChild, GW_HWNDNEXT);
			//}
         while(hChild)
          {
				GetWindowText(hChild,szWindosText,MAX_PATH);
				TCHAR szText[]=_T("&Make New Folder");
				if(lstrcmp(szWindosText,szText)==0)
				{      
                                        //find and keep the make new folder button handle
					hMakeNewFolder=hChild;   
					//::OutputDebugString(_T("find the control"));
					//::OutputDebugString(szWindosText);
					break;
				}
				hChild = GetNextWindow(hChild, GW_HWNDNEXT);
			}
			
		}
		break;
	}
	return 0;
}

[jingzhongrong]

调用SHBrowserForFolder之前先
::CoInitialize(NULL)