好的，我找到了导致这个问题的原因.确实，我在创建项目时错过了配置项目，更准确地说，我在配置 libxml 时出了点问题.现在，它可以使用相同的代码正常工作.

OK, I found out what was causing this problem. Indeed, i miss configured the project when creating it, to be more precise I have something wrong when i configured libxml. Right now, it working correctly with the same code.

PS:我认为 XMPP iOS Framework 还不稳定，所以我想我会改变应用程序内的聊天技术.

PS: I think that the XMPP iOS Framework is not still stable, so I think that I will change chat technology within the application.