/// <summary>
    /// Add a new exit event listener.
    /// </summary>

    static public void AddOnExit(Component mb, OnTriggerCallback callback)
    {
        ProximityManager pro = GetInstance(mb);

        foreach (TriggerListener p in pro.mOnExit)
        {
            if (p.mb == mb && p.callback == callback)
            {
                return;
            }
        }

        TriggerListener ent = new TriggerListener();

        ent.mb       = mb;
        ent.callback = callback;
        pro.mOnExit.Add(ent);
    }
 private void OnDestroy()
 {
     _onEnter = null;
     _onExit = null;
 }
 private void OnDestroy()
 {
     _onStay = null;
 }
 private void OnDestroy()
 {
     _onEnter = null;
     _onExit  = null;
 }
 private void OnDestroy()
 {
     _onStay = null;
 }