iOS判断是否插入耳机

//获取设备状态，是否插入耳机，如果插入耳机，则返回“YES"
+ (BOOL)isHeadphone{
UInt32 propertySize = sizeof(CFStringRef);
CFStringRef state = nil;
AudioSessionGetProperty(kAudioSessionProperty_AudioRoute,&propertySize,&state);
//return @"Headphone" or @"Speaker"
if ([(NSString *)state isEqualToString:@"Headphone"] ||[(NSString *)state isEqualToString:@"HeadsetInOut"]) {
return YES;
}else {
return NO;
}
}