class CMyFileDialog: public CFileDialogImpl
{
public:
CMyFileDialog(BOOL bOpenFileDialog, // TRUE for FileOpen, FALSE for FileSaveAs
LPCTSTR lpszDefExt = NULL,
LPCTSTR lpszFileName = NULL,
DWORD dwFlags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
LPCTSTR lpszFilter = NULL,
HWND hWndParent = NULL)
: CFileDialogImpl(bOpenFileDialog, lpszDefExt, lpszFileName, dwFlags, lpszFilter, hWndParent){ }

// Maps  
BEGIN\_MSG\_MAP(CMyFileDialog)  
    CHAIN\_MSG\_MAP(CFileDialogImpl<CMyFileDialog>)  
END\_MSG\_MAP()

//重载此函数；实现居中  
void OnInitDone ( LPOFNOTIFY lpon )  
{  
    GetFileDialogWindow().CenterWindow(lpon->lpOFN->hwndOwner);  
}

};

重写FileDialog,重载OnInitDone，实现居中，引用代码如下：

void xxx::SelectUpgradeFile()
{
char szFilters[] = _T("升级文件 (*.ram)\0*.ram\0全部文件(*.*)\0*.*\0\0");
CMyFileDialog fileDlg(TRUE,NULL, NULL,OFN_FILEMUSTEXIST|OFN_HIDEREADONLY,szFilters );//szFilters

char strBuffer\[MAX\_PATH\] = {};  
fileDlg.m\_ofn.lpstrFile = strBuffer;  
fileDlg.m\_ofn.nMaxFile = MAX\_PATH;  
if (fileDlg.DoModal() != IDOK)  
{  
    ImmsMessageBox(m\_PaintManager.GetPaintWindow(),\_T("升级设备失败！"),\_T("提示"),MB\_OK);  
    return ;  
}  
m\_strEquipmentUpgradeFileName = fileDlg.m\_ofn.lpstrFile;  
if (m\_strEquipmentUpgradeFileName.Right().CompareNoCase(".ram")!=)  
{  
    ImmsMessageBox(m\_PaintManager.GetPaintWindow(),\_T("选择的文件不是编解码器升级文件！"),\_T("提示"),MB\_OK|MB\_ICONERROR);  
    return ;  
}

CEditUI \*pFileName = static\_cast<CEditUI \*>(m\_PaintManager.FindControl(ctrl\_device\_data\_manager\_decoder\_equi\_upgrade\_select\_file));  
if(!pFileName)  
    return;  
pFileName->SetText(m\_strEquipmentUpgradeFileName);

}