iphone打开扬声器

+( void ) isOpenSpeaker:(bool)bOpen
{
    UInt32 route;
    OSStatus error;
    UInt32 sessionCategory = kAudioSessionCategory_PlayAndRecord;

    error = AudioSessionSetProperty (
                                     kAudioSessionProperty_AudioCategory,
                                     sizeof (sessionCategory),
                                     &sessionCategory
                                     );

    route = bOpen?kAudioSessionOverrideAudioRoute_Speaker:kAudioSessionOverrideAudioRoute_None;
    error = AudioSessionSetProperty(kAudioSessionProperty_OverrideAudioRoute, sizeof(route), &route);

}

#import <AudioToolbox/AudioToolbox.h>