1

我得到这个代码来判断耳机是否连接:

这在 viewDidLoad 中:

AudioSessionAddPropertyListener(kAudioSessionProperty_AudioRouteChange, audioSessionPropertyListener, nil);

这个功能:

void audioSessionPropertyListener(void* inClientData, AudioSessionPropertyID inID,
                              UInt32 inDataSize, const void* inData) {
UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;

// Determines the reason for the route change, to ensure that it is not
//      because of a category change.
CFDictionaryRef routeChangeDictionary = inData;    
CFNumberRef routeChangeReasonRef = CFDictionaryGetValue (routeChangeDictionary,CFSTR (kAudioSession_AudioRouteChangeKey_Reason));

SInt32 routeChangeReason;    
CFNumberGetValue (routeChangeReasonRef, kCFNumberSInt32Type, &routeChangeReason);

// "Old device unavailable" indicates that a headset was unplugged, or that the
//  device was removed from a dock connector that supports audio output. 
if (routeChangeReason != kAudioSessionRouteChangeReason_OldDeviceUnavailable) {
    [[Cubic_01AppDelegate sharedInstance] setDongleIsDisonnected];
}


if (!isHeadsetPluggedIn()) 
{
    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);
}
else 
{
    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute, sizeof(audioRouteOverride), &audioRouteOverride);
}    

}

这个功能:

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

OSStatus error = AudioSessionGetProperty (kAudioSessionProperty_AudioRoute,
                                          &routeSize,
                                          &route
                                          );    
NSLog(@"%@", route);

BOOL isPluggedIn = !error && (route != NULL) && ([(NSString*)route rangeOfString:@"Head"].location != NSNotFound);

if (isPluggedIn) {
    [[Cubic_01AppDelegate sharedInstance] setDongleIsConnected];
} else {
    [[Cubic_01AppDelegate sharedInstance] setDongleIsDisonnected];
}

return (isPluggedIn);

}

谁能帮助告诉我为什么在应用程序启动之前已经连接耳机时没有调用 audioSessionPropertyListener 函数?

4

1 回答 1

0

您需要检查应用程序的加载/启动。基本上你应该可以调用:

- (void) viewDidLoad
{
    isHeadsetPluggedIn()
}

如果您在连接耳机之前尚未启动应用程序,则尚未设置属性侦听器。请注意,属性侦听器仅检查更改。

因此,您需要对应用程序的加载/启动进行检查。您可以直接获取 AudioSession 属性,而无需使用侦听器并因此进行解析。这正是您在 isHeadsetPluggedIn() 中所做的,正如您所说:

OSStatus error = AudioSessionGetProperty (kAudioSessionProperty_AudioRoute,
                                      &routeSize,
                                      &route);  

此方法可以在目标 c 和 c++ 函数中调用。初始化后,可以在任何地方调用它来获取 AudioSession 的任何属性。

于 2011-11-29T18:24:00.723 回答