音频播放AVAudioPlayer后台播放

// 1. info.plist
key：Required background modes
value: array @[App plays audio or streams audio/video using Airplay]

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

// 1. 音频后台播放
// 01- info.plist
// 02- appDelegate设置会话
//后台播放音频设置
// 会话
AVAudioSession *session = [AVAudioSession sharedInstance];
// 激活当前会话
[session setActive:YES error:nil];
// 设置会话类型为后台播放
[session setCategory:AVAudioSessionCategoryPlayback error:nil];
return YES;
}