耳机是否已插入？ IOS 7

为 iPhone 开发一个应用程序，其中包含也需要通过耳机收听的音频文件。

如何检查耳机是否未插入，以便我可以告诉用户插入耳机。

我有来自另一个线程的以下代码，但不推荐使用 audioSessionGetProperty 方法。任何人都知道如何更改以下代码以使其工作或拥有自己的代码/解决方案。

Thanks.

- (BOOL)isHeadsetPluggedIn {
    UInt32 routeSize = sizeof (CFStringRef);
    CFStringRef route;


    //Maybe changing it to something like the following would work for iOS7?
    //AVAudioSession* session = [AVAudioSession sharedInstance];
    //OSStatus error = [session setCategory:kAudioSessionProperty_AudioRoute...?


    //the line below is whats giving me the warning
    OSStatus error = AudioSessionGetProperty (kAudioSessionProperty_AudioRoute,
                                              &routeSize,
                                              &route);

    /* Known values of route:
     * "Headset"
     * "Headphone"
     * "Speaker"
     * "SpeakerAndMicrophone"
     * "HeadphonesAndMicrophone"
     * "HeadsetInOut"
     * "ReceiverAndMicrophone"
     * "Lineout"
     */

    if (!error && (route != NULL)) {

        NSString* routeStr = (__bridge NSString*)route;

        NSRange headphoneRange = [routeStr rangeOfString : @"Head"];

        if (headphoneRange.location != NSNotFound) return YES;

    }

    return NO;
}

这应该可行，但我现在无法测试，我会在晚上进行。

- (BOOL)isHeadsetPluggedIn {
    AVAudioSessionRouteDescription* route = [[AVAudioSession sharedInstance] currentRoute];
    for (AVAudioSessionPortDescription* desc in [route outputs]) {
        if ([[desc portType] isEqualToString:AVAudioSessionPortHeadphones])
            return YES;
    }
    return NO;
}