windows下C语言调用系统文件选择对话框

代码片段，在windows下用C语言调用文件选择对话框，以备忘

#define DEFAULT_DIR ""
char extraction_path[MAX_PATH] = DEFAULT_DIR;


/*
 * Browse for a folder and update the folder edit box
 * Will use the newer IFileOpenDialog if *compiled* for Vista or later
 */
void browse_for_folder(void) {

	BROWSEINFOW bi;
	LPITEMIDLIST pidl;

#if (_WIN32_WINNT >= 0x0600)	// Vista and later
	WCHAR *wpath;
	size_t i;
	HRESULT hr;
	IShellItem *psi = NULL;
	IShellItem *si_path = NULL;	// Automatically freed
	IFileOpenDialog *pfod = NULL;
	WCHAR *fname;
	char* tmp_path = NULL;

	// Even if we have Vista support with the compiler,
	// it does not mean we have the Vista API available
	INIT_VISTA_SHELL32;
	if (IS_VISTA_SHELL32_AVAILABLE) {
		hr = CoCreateInstance(&CLSID_FileOpenDialog, NULL, CLSCTX_INPROC,
			&IID_IFileOpenDialog, (LPVOID)&pfod);
		if (FAILED(hr)) {
			dprintf("CoCreateInstance for FileOpenDialog failed: error %X", hr);
			pfod = NULL;	// Just in case
			goto fallback;
		}
		hr = pfod->lpVtbl->SetOptions(pfod, FOS_PICKFOLDERS);
		if (FAILED(hr)) {
			dprintf("Failed to set folder option for FileOpenDialog: error %X", hr);
			goto fallback;
		}
		// Set the initial folder (if the path is invalid, will simply use last)
		wpath = utf8_to_wchar(extraction_path);
		// The new IFileOpenDialog makes us split the path
		fname = NULL;
		if ((wpath != NULL) && (wcslen(wpath) >= 1)) {
			for (i=wcslen(wpath)-1; i!=0; i--) {
				if (wpath[i] == L'\') {
					wpath[i] = 0;
					fname = &wpath[i+1];
					break;
				}
			}
		}

		hr = (*pSHCreateItemFromParsingName)(wpath, NULL, &IID_IShellItem, (LPVOID)&si_path);
		if (SUCCEEDED(hr)) {
			if (wpath != NULL) {
				hr = pfod->lpVtbl->SetFolder(pfod, si_path);
			}
			if (fname != NULL) {
				hr = pfod->lpVtbl->SetFileName(pfod, fname);
			}
		}
		safe_free(wpath);

		hr = pfod->lpVtbl->Show(pfod, hMain);
		if (SUCCEEDED(hr)) {
			hr = pfod->lpVtbl->GetResult(pfod, &psi);
			if (SUCCEEDED(hr)) {
				psi->lpVtbl->GetDisplayName(psi, SIGDN_FILESYSPATH, &wpath);
				tmp_path = wchar_to_utf8(wpath);
				CoTaskMemFree(wpath);
				if (tmp_path == NULL) {
					dprintf("Could not convert path");
				} else {
					safe_strcpy(extraction_path, MAX_PATH, tmp_path);
					safe_free(tmp_path);
				}
			} else {
				dprintf("Failed to set folder option for FileOpenDialog: error %X", hr);
			}
		} else if ((hr & 0xFFFF) != ERROR_CANCELLED) {
			// If it's not a user cancel, assume the dialog didn't show and fallback
			dprintf("could not show FileOpenDialog: error %X", hr);
			goto fallback;
		}
		pfod->lpVtbl->Release(pfod);
		return;
	}
fallback:
	if (pfod != NULL) {
		pfod->lpVtbl->Release(pfod);
	}
#endif
	INIT_XP_SHELL32;
	memset(&bi, 0, sizeof(BROWSEINFOW));
	bi.hwndOwner = hMain;
	bi.lpszTitle = L"Please select the installation folder:";
	bi.lpfn = browseinfo_callback;
	// BIF_NONEWFOLDERBUTTON = 0x00000200 is unknown on MinGW
	bi.ulFlags = BIF_RETURNFSANCESTORS | BIF_RETURNONLYFSDIRS |
		BIF_DONTGOBELOWDOMAIN | BIF_EDITBOX | 0x00000200;
	pidl = SHBrowseForFolderW(&bi);
	if (pidl != NULL) {
		CoTaskMemFree(pidl);
	}
}