iOS音量事件与回调

添加事件监听

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(volumeDidChange:)name:@"AVSystemController_SystemVolumeDidChangeNotification" object:nil];
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

事件回调

- (void)volumeDidChange:(NSNotification *)notification
{
    double i= [(NSNumber *)notification.userInfo[@"AVSystemController_AudioVolumeNotificationParameter"]  doubleValue];
    NSLog(@"=当前音量：%f",i);

}