//录音之前，先调用下面的语句，询问用户是否可以访问他的隐私设备麦克风

[[AVAudioSession sharedInstance] requestRecordPermission:^(BOOL granted)

{}];



if([[[AVAudioSessionsharedInstance]category]isEqualToString:AVAudioSessionCategoryPlayback])

{

//切换为听筒播放

[[AVAudioSessionsharedInstance]setCategory:AVAudioSessionCategoryPlayAndRecorderror:nil];

[selfshowTipInfo:@"切换为听筒模式"];

}

else

{

//切换为扬声器播放

[[AVAudioSessionsharedInstance]setCategory:AVAudioSessionCategoryPlaybackerror:nil];

[selfshowTipInfo:@"切换为扬声器模式"];

}