如何从LinphoneFriend获取联系人在线状态？

Question

我使用linphone库最新版本。我想显示sip联系人状态。这是我的代码。

LinphoneFriend[] friends = LinphoneManager.getLc().getFriendList();
                    if (!ContactsManager.getInstance().isContactPresenceDisabled() && friends != null && contact.hasAddress()) {
                        friendStatus.setVisibility(View.VISIBLE);

                        String friendSipAddress = "";
                        for (LinphoneNumberOrAddress noa : contact.getNumbersOrAddresses()) {
                            if (noa.isSIPAddress()) {
                                friendSipAddress = noa.getValue();
                            }
                        }
                        LinphoneFriend friend = null;
                        for (int i = 0; i < friends.length; i++) {
                            Log.e("Friend","Addr " + friends[i].getAddress().asStringUriOnly());
                            Log.e("Friend","Name " + friends[i].getAddress().getDisplayName());
                            if (friends[i].getAddress().asStringUriOnly().equalsIgnoreCase(friendSipAddress)) {
                                friend = friends[i];
                                break;
                            }
                        }

                        if(friend!=null) {
                            PresenceModel presenceModel = friend.getPresenceModel();
                            if (presenceModel != null) {
                                //PresenceActivityType presenceActivity = friends[0].getPresenceModel().getActivity().getType();
                                PresenceActivityType presenceActivity = presenceModel.getActivity().getType();
                                android.util.Log.e("Linphone",friend.getName()+" " + presenceActivity);
                                if (presenceActivity == PresenceActivityType.Online) {
                                    friendStatus.setImageResource(R.drawable.led_connected);
                                } else if (presenceActivity == PresenceActivityType.Busy) {
                                    friendStatus.setImageResource(R.drawable.led_error);
                                } else if (presenceActivity == PresenceActivityType.Away) {
                                    friendStatus.setImageResource(R.drawable.led_inprogress);
                                } else if (presenceActivity == PresenceActivityType.OnThePhone) {
                                    friendStatus.setImageResource(R.drawable.on_phone);
                                } else if (presenceActivity == PresenceActivityType.Offline) {
                                    friendStatus.setImageResource(R.drawable.led_disconnected);
                                } else {
                                    friendStatus.setImageResource(R.drawable.led_disconnected);
                                }
                            } else {
                                friendStatus.setImageResource(R.drawable.led_error);
                                //Log.e("Linphone", "led_error");
                            }
                        } else {
                            //Log.e("Friend","friend null");
                        }
                    } else {
                        Log.e("Friend","friend visibility gone");
                        friendStatus.setVisibility(View.INVISIBLE);
                    }

但是LinphoneFriend对象总是给出PresenceModel。如何从linphonefriend获取状态模型？