请教个C# override方法问题？

下面这个override方法，ReciveUdpMsg();方法只能调用一次，第二次就进不去这个方法了，不知道怎么回事？ /// <summary>
        /// 重写
        /// </summary>
        /// <param name="m"></param>
        protected  override void WndProc(ref Message m)
        {
            if (m.Msg == WM_GRAPHNOTIFY)
            {
                int lEventCode;
                int lParam1, lParam2;
                while (true)
                {
                    try
                    {
                        m_objMediaEventEx.GetEvent(out lEventCode, out lParam1, out lParam2, 0);
                        m_objMediaEventEx.FreeEventParams(lEventCode, lParam1, lParam2);                        if (lEventCode == EC_COMPLETE)
                        {
                            this.Clear();
                            if (j == 1 || j == i)
                            {
                                LoadStartVideos();
                            }
                            else
                            {
                                LoadVideo1();     
                            }
                            ReciveUdpMsg();
                        }
                    }
                    catch (Exception)
                    {
                        break;
                    }
                }
            }
            base.WndProc(ref m);
        }