public void OnIq(object sender, IQ iq) { if (iq == null) return; string id = iq.Id; if(id == null) return; TrackerData td; lock (m_grabbing) { td = (TrackerData) m_grabbing[id]; if (td == null) { return; } m_grabbing.Remove(id); } td.cb(this, iq, td.data); }