1.带内注册（In-band registration）的概念

带内注册指的是未在你的服务器上开通账号的用户可以通过xmpp协议注册新账号。相反的概念是带外注册（out-of-band registration），例如 你必须到某个指定的web页面进行注册。

如果服务器允许带内注册，那么我们就可以通过自己开发的客户端注册新账号。与带内注册相关的协议是XEP-0077。

2.使用XMPPFramework进行带内注册

XMPPStream.h中声明了进行简单带内注册(提供用户名和密码进行注册)的函数

- (BOOL)registerWithPassword:(NSString *)password error:(NSError **)errPtr;

注册前需要先建立stream连接, 因为没有帐号,所以需要建立匿名连接

NSError *err; 
NSString *tjid = [[NSString alloc] initWithFormat:@"anonymous@%@", server.text];
[[delegate xmppStream] setMyJID:[XMPPJID jidWithString:tjid]];
if ( ![[delegate xmppStream] connect:&err])
{
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"连接服务器失败" 
message:[err localizedDescription]
delegate:nil 
cancelButtonTitle:@"Ok" 
otherButtonTitles:nil];
[alertView show];

}

建立连接之后, 不需要进行用户验证, 可以如下处理 – 如果是在注册,则跳过验证这一步

- (void)xmppStreamDidConnect:(XMPPStream *)sender
{
    DDLogVerbose(@"%@: %@", THIS_FILE, THIS_METHOD);

    isXmppConnected = YES;

    NSError *error = nil;
    if (isRegister == YES)
        return;

    if (![[self xmppStream] authenticateWithPassword:password error:&error])
    {
        DDLogError(@"Error authenticating: %@", error);
    }
}

xmppStream connect 是立即返回的, 所以connect返回并不能说明连接已经建立好. [delegate xmppStream] isConnected 为YES时才能确定连接已经建立好.

连接建立好之后,我们就可以发注册信息

NSString *jid = [[NSString alloc] initWithFormat:@"%@@%@", user.text, server.text];
[[delegate xmppStream] setMyJID:[XMPPJID jidWithString:jid]];
NSError *error=nil;
if (![[delegate xmppStream] registerWithPassword:password.text error:&error])
{
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"创建帐号失败" 
message:[error localizedDescription]
delegate:nil 
cancelButtonTitle:@"Ok" 
otherButtonTitles:nil];
[alertView show];
}

registerWithPassword:error 方法也是立即返回的

需要通过代理方法来判断注册是否成功

注册成功会调用:- (void)xmppStreamDidRegister:(XMPPStream *)sender 注册失败会调用:- (void)xmppStream:(XMPPStream *)sender didNotRegister:(NSXMLElement *)error

- (void)xmppStreamDidRegister:(XMPPStream *)sender
{
    DDLogVerbose(@"%@: %@", THIS_FILE, THIS_METHOD);
    registerSuccess = YES;
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"创建帐号成功" 
                                                        message:@""
                                                       delegate:self 
                                              cancelButtonTitle:@"Ok" 
                                              otherButtonTitles:nil];
    [alertView show];
}

- (void)xmppStream:(XMPPStream *)sender didNotRegister:(NSXMLElement *)error
{
    DDLogVerbose(@"%@: %@", THIS_FILE, THIS_METHOD);
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"创建帐号失败" 
                                                        message:@"用户名冲突"
                                                       delegate:nil 
                                              cancelButtonTitle:@"Ok" 
                                              otherButtonTitles:nil];
    [alertView show];
}