实现XMPPStreamDelegate协议中的方法

XMPPStreamDelegate是一个协议，用于处理XMPPStream的事件和回调。以下是XMPPStreamDelegate协议中的常用方法：

//连接成功
- (void)xmppStreamDidConnect:(XMPPStream *)sender;

//连接超时
- (void)xmppStreamConnectDidTimeout:(XMPPStream *)sender;

//连接断开
- (void)xmppStreamDidDisconnect:(XMPPStream *)sender withError:(NSError *)error;

//认证成功
- (void)xmppStreamDidAuthenticate:(XMPPStream *)sender;

//认证失败
- (void)xmppStream:(XMPPStream *)sender didNotAuthenticate:(NSXMLElement *)error;

//接收到消息
- (void)xmppStream:(XMPPStream *)sender didReceiveMessage:(XMPPMessage *)message;

//接收到好友请求
- (void)xmppStream:(XMPPStream *)sender didReceivePresence:(XMPPPresence *)presence;

//发送消息成功
- (void)xmppStream:(XMPPStream *)sender didSendMessage:(XMPPMessage *)message;

//发送消息失败
- (void)xmppStream:(XMPPStream *)sender didFailToSendMessage:(XMPPMessage *)message error:(NSError *)error;

在实现XMPPStreamDelegate协议时，需要将自己的类指定为XMPPStream的代理，如下所示：

XMPPStream *xmppStream = [[XMPPStream alloc] init];
[xmppStream addDelegate:self delegateQueue:dispatch_get_main_queue()];

然后就可以在实现XMPPStreamDelegate协议中的方法来处理相应的事件和回调了。