1.在后台可以继续播放音频
To play sound in the background, make sure to add the following to the Info.plist file.
Info.plist
<key>UIBackgroundModes</key> <array> <string>audio</string> </array>
ios 后台模式
原文：http://www.cnblogs.com/hd1992/p/5946775.html
