进度条设置错误原因?

请问下列错误原因?要怎样才能实现复制文件进度条.请帮我改一下.
DWORD CALLBACK CopyProgress(LARGE_INTEGER TotalFileSize, LARGE_INTEGER TotalBytesTransferred,
LARGE_INTEGER StreamSize, LARGE_INTEGER StreamBytesTransferred,DWORD dwStreamNumber,
DWORD dwCallbackReason,HANDLE hSourceFile,HANDLE hDestinationFile, LPVOID lpData )
{
CJinDuDlg*   ptr   =   (CJinDuDlg*)lpData;
ptr->m_Progress.SetPos(TotalBytesTransferred.LowPart * 100 / TotalFileSize.LowPart);
return PROGRESS_CONTINUE;
}
void CJinDuDlg::OnButton1() 
{
m_Progress.SetRange(0,100);//m_Progress为进度条控件
m_Progress.SetPos(10);
CopyFileEx("D:\\open\\down\\groups\\2.rar","D:\\GAME\\2.rar",
(LPPROGRESS_ROUTINE)CopyProgress,(LPVOID)&m_Progress,FALSE,COPY_FILE_RESTARTABLE);
}