判断设备是否插入耳机

//获取设备状态，是否插入耳机，如果插入耳机，则返回“YES" BY Leisure 

+ (BOOL)isHeadphone
{
UInt32 propertySize = sizeof(CFStringRef);
CFStringRef state = nil;
AudioSessionGetProperty(kAudioSessionProperty_AudioRoute
,&propertySize,&state);
//return @"Headphone" or @"Speaker" and so on.
//根据状态判断是否为耳机状态
if ([(NSString *)state isEqualToString:@"Headphone"] ||[(NSString *)state isEqualToString:@"HeadsetInOut"]) 
{
return YES;
}
else {
return NO;
} 
}