无法在ios中提供脱机xmpp消息

Question

我在ios应用程序中使用xmpp framwork来支持即时消息，我需要确保在离线用户上线时会收到离线消息，但我发现在线用户尝试向其发送消息时离线用户，在线用户很快就会离线，消息无法成功发送，有没有人遇到过这个问题？

以下是我的相关代码：

pragma XMPP协议方法

- （无效）setupStream {

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

}

- （无效）goOnline {

XMPPPresence *presence = [XMPPPresence presence];
[[self xmppStream] sendElement:presence];

}

- （无效）goOffline {

XMPPPresence *presence = [XMPPPresence presenceWithType:@"unavailable"];
[[self xmppStream] sendElement:presence];

}

- （BOOL）connect：（NSString *）用户名密码：（NSString *）pwd {

if (xmppStream == nil) {
    [self setupStream];
}

if (![xmppStream isDisconnected]) {
    return YES;
}

if (username == nil || pwd == nil) {
    return NO;
}

[xmppStream setMyJID:[XMPPJID jidWithString:[NSString stringWithFormat:@"%@@%@", username,LoversClock_Openfire_ServerName]]];
[xmppStream setHostName:LoversClock_Openfire_DomainName];
[xmppStream setHostPort:LoversClock_Openfire_XMPP_Port];
self.password = pwd;

NSError *error = nil;
if (![xmppStream connect:&error]) {
    NSLog(@"cant connect %@", LoversClock_Openfire_DomainName);
    return NO;
}

return YES;

}

- （无效）断开{

[self goOffline];
[xmppStream disconnect];

}

- （void）sendMessage：（DDXMLElement *）message {

[_arrayXMPPMessage addObject:message];
if (_isOFOnline) {
    [[self xmppStream] sendElement:message];
}

}

pragma标记XMPPStreamDelegate方法

- （void）xmppStreamDidConnect：（XMPPStream *）sender {

NSError *error = nil;
[[self xmppStream] authenticateWithPassword:password error:&error];

}

- （void）xmppStreamDidAuthenticate：（XMPPStream *）sender {

if (reconnectTimer!=nil && [reconnectTimer isValid]) {
    [reconnectTimer invalidate];
}
reconnectTimer = nil;
[self goOnline];
_isOFOnline = YES;
[self sendOfflineMsg];
[onlineStateView setBackgroundColor:[UIColor greenColor]];

}

- （void）xmppStreamDidDisconnect：（XMPPStream *）sender withError：（NSError *）error {

_isOFOnline = NO;
if (!isOffline && !(reconnectTimer!=nil && [reconnectTimer isValid])) {
    NSDictionary* personalInfoDict = [ConfigRestoreHelper sharedInstance].myPersonalInfo;
    if (personalInfoDict != nil) {
        [self connect:[personalInfoDict objectForKey:KEY_USERNAME] password:[personalInfoDict objectForKey:KEY_PASSWORD]];
        reconnectTimer = [NSTimer scheduledTimerWithTimeInterval:20 target:self selector:@selector(reconnectFired:) userInfo:nil repeats:YES];
    }
}
[onlineStateView setBackgroundColor:[UIColor yellowColor]];

}

以下是我的消息示例

        NSXMLElement *body = [NSXMLElement elementWithName:@"body"];
        [body addAttributeWithName:@"clockid" stringValue:_clockId];
        [body addAttributeWithName:@"bedclocktype" stringValue:SafeGetStringValue([speechDict objectForKey:@"bedclocktype"])];
        [body addAttributeWithName:@"bedclockpath" stringValue:SafeGetStringValue([speechDict objectForKey:@"bedclockpath"])];

        NSXMLElement *message = [NSXMLElement elementWithName:@"message"];
        [message addAttributeWithName:@"type" stringValue:XMPP_MESSAGE_WAKETAUP];
        [message addAttributeWithName:@"to" stringValue:[NSString stringWithFormat:@"%@@%@", toUser,LoversClock_Openfire_ServerName]];
        [message addAttributeWithName:@"fromuser" stringValue:fromUser];
        [message addAttributeWithName:@"destuserid" stringValue:[[ConfigRestoreHelper sharedInstance].taPersonalInfo objectForKey:KEY_USERID]];
        [message addChild:body];

        [(AppDelegate*)[UIApplication sharedApplication].delegate sendMessage:message];