smack RosterListener 在 Android 中不起作用

目前我正在使用 Xmpp SMACK API 工作聊天应用程序。但是当我调用 addrosterListener 时，我没有获得当前状态。我必须参考http://www.igniterealtime.org/builds/smack/docs/3.2.2/javadoc/org/jivesoftware/smack/RosterListener.html http://www.igniterealtime.org/builds/smack/docs/3.2.2/javadoc/org/jivesoftware/smack/RosterListener.html。请帮我。

roster.addRosterListener(new RosterListener() {
                        @Override
                        public void presenceChanged(Presence presence) {


                            Log.d("pewsence ", "pewsence Status: " + presence.getFrom());
                            Log.d("pewsence ", "pewsence to Status: "
                                    + presence.getTo() + " " + presence);

                            // Called when the presence of a roster entry is
                            // changed
                        }

                        @Override
                        public void entriesUpdated(Collection<String> arg0) {
                            // Called when a roster entries are updated.

                        }

                        @Override
                        public void entriesDeleted(Collection<String> arg0) {
                            // Called when a roster entries are removed.
                        }

                        @Override
                        public void entriesAdded(Collection<String> arg0) {
                            // Called when a roster entries are added.
                        }
                    });
                }
            }
        });

这个监听器是在活动创建时调用的。我认为参考所有文档，当状态发生变化时，这个监听器会自动调用。

提前致谢。

roster = connection.getRoster();

            // Get all rosters
            Log.i("roster", "roster=" + connection.isConnected() + "-" + roster);
            Collection<RosterEntry> entries = roster.getEntries();
            // loop through
            for (RosterEntry entry : entries) {
                Presence entryPresence = roster.getPresence(entry.getUser());
                Presence.Type userType = entryPresence.getType();

            }

使用此代码，您必须获得所有在线或离线用户。并且您可以与任何人聊天。