XMPP学习记录四：关于接受，发送消息和获取好友上下线的状态

消息

1. //收到消息
2. - (void)xmppStream:(XMPPStream *)sender didReceiveMessage:(XMPPMessage *)message{
4. // NSLog(@message = %@, message);
5. //消息的内容
6. NSString *msg = [[message elementForName:@body] stringValue];
7. //消息发送者
8. NSString *from = [[message attributeForName:@from] stringValue];
10. /****在此处****/
11. //通知聊天页面有新消息，需要处理
13. }

    
    发送消息

    [cpp]
    1. //发送消息的xml格式
    2. to='接收者账号'
    3. type='chat'>

    5. //代码组装

       [cpp] view plaincopyprint
       1. NSString *message = @HELLO WORLD;
       2. NSXMLElement *body = [NSXMLElement elementWithName:@body];
       3. [body setStringValue:message];
       5. //生成XML消息文档
       6. NSXMLElement *mes = [NSXMLElement elementWithName:@message];
       7. //消息类型
       8. [mes addAttributeWithName:@type stringValue:@chat];
       9. //发送给谁
       10. [mes addAttributeWithName:@to stringValue:@接受者账号];
       11. //由谁发送
       12. [mes addAttributeWithName:@from stringValue:@发送者账号];
       13. //组合
       14. [mes addChild:body];
       16. //发送消息
       17. [[self xmppStream] sendElement:mes];
           
           

           好友上下线通知

           [cpp]
           1. - (void)xmppStream:(XMPPStream *)sender didReceivePresence:(XMPPPresence *)presence
           2. {
           3. //取得好友状态
           4. NSString *presenceType = [presence type]; //online/offline
           5. //当前用户
           6. NSString *userId = [[sender myJID] user];
           7. //在线用户
           8. NSString *presenceFromUser = [[presence from] user];
           9. /*
           10. //如果不是自己，如果涉及多段登录，此处最好加上else，如果是自己离线的话，调用上线协议
           11. XMPPPresence *presence = [XMPPPresence presence];
           12. [[self xmppStream] sendElement:presence];
           13. */
           14. if (![presenceFromUser isEqualToString:userId])
           15. {
           16. //用户在线
           17. if ([presenceType isEqualToString:@available])
           18. {
           19. //列表和数据库都要相应改变
           20. }else if ([presenceType isEqualToString:@unavailable])//用户不在线
           21. {
           22. //列表和数据库都要相应改变
           23. }
           24. }
           25. }