1. Im Confirm, Call Confirm等。 reveive push notificaion => Activate application => autologin =>
server send messgage(如有人给你发消息） to client until the client send confrim to tell server, the message is received and displayed in UI. 对用户来说就像是对方刚发的那条，实际上则是server重新发送的。
具体的有时间再写。。。