录音时候音频的外放

AVAudioSession*audioSession=[AVAudioSessionsharedInstance];

//1.设置为播放和录音状态，以便可以在录制完之后播放录音AVAudioSessionCategoryAmbient AVAudioSessionCategoryPlayAndRecord

[audioSessionsetCategory:AVAudioSessionCategoryPlayAndRecorderror:nil];

[audioSessionsetActive:isActiveerror:nil];

[audioSessionoverrideOutputAudioPort:AVAudioSessionPortOverrideSpeakererror:nil];

//2.这个方法相当于上面方法的和但是比overrideOutputAudioPort时效性更长

//[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker error:nil];

UInt32doChangeDefaultRoute =1;

//3.下面方法相当于overrideOutputAudioPort但实效性更长会影响其他应用音频的使用

//kAudioSessionProperty_OverrideAudioRoute kAudioSessionProperty_OverrideCategoryDefaultToSpeaker

AudioSessionSetProperty(

kAudioSessionProperty_OverrideCategoryDefaultToSpeaker,

sizeof(doChangeDefaultRoute),

&doChangeDefaultRoute

);

／／加两个地址

http://blog.csdn.net/xy5811/article/details/8563137

https://developer.apple.com/library/content/qa/qa1754/_index.html