Question

我正在编写一个iPhone应用程序，涉及在后台通过VoIP套接字处理来自服务器的网络事件。我已成功设置套接字，.plist中的后台服务信息以及相应的流，但我无法弄清楚如何在回调中做任何有用的事情。我不知道如何从回调函数中访问我的应用程序的其余状态。这是我在AppDelegate中设置连接的地方：

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
    NSLog(@"AppDelegate: didFinishLaunchingWithOptions");
    // Override point for customization after application launch.

    // Add the view controller's view to the window and display.
    [self.window addSubview:viewController.view];
    [self.window makeKeyAndVisible];

    CFReadStreamRef readStream; 
    CFWriteStreamRef writeStream;
    CFHostRef host = CFHostCreateWithName(kCFAllocatorDefault, (CFStringRef)@"irc.freenode.net");
    CFStreamCreatePairWithSocketToCFHost(kCFAllocatorDefault, host, 6667, &readStream, &writeStream);
    CFReadStreamSetProperty(readStream, kCFStreamNetworkServiceType, kCFStreamNetworkServiceTypeVoIP);
    CFWriteStreamSetProperty(writeStream, kCFStreamNetworkServiceType, kCFStreamNetworkServiceTypeVoIP);

    CFStreamClientContext myContext = {
        0,
        viewController,
        (void *(*)(void *info))CFRetain,
        (void (*)(void *info))CFRelease,
        (CFStringRef (*)(void *info))CFCopyDescription
    };

    CFOptionFlags registeredEvents = kCFStreamEventHasBytesAvailable |
    kCFStreamEventErrorOccurred | kCFStreamEventEndEncountered;

    if(CFReadStreamSetClient(readStream, registeredEvents, clientCB, &myContext)) {
        CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
    }

    if (!CFReadStreamOpen(readStream)) {
        NSLog(@"Read stream could not be opened");
    }
    else {
        NSLog(@"Successfully opened read stream");
    }
    return YES;
}

这是CFStream事件的回调函数，我遇到了问题：

void clientCB(CFReadStreamRef stream, CFStreamEventType event, void* myPtr) {
    switch(event) {
        case kCFStreamEventHasBytesAvailable:{
            UInt8 buf[32];
            CFIndex bytesRead = CFReadStreamRead(stream, buf, 32);
            if (bytesRead > 0) {
                NSLog(@"Readstream Not Empty %i", buf[0]);//dummy debug marker
            }
            //I WANT TO ACCESS CLASSES, PROPERTIES, FUNCTIONS, ETC. ABOUT THE REST OF MY PROGRAM HERE (E.G. GET A WORKING POINTER BACK TO THE MAIN APPDELEGATE).
        break;
    }
    case kCFStreamEventErrorOccurred:
    case kCFStreamEventEndEncountered:
    default:
        break;
}
}

这两个函数都在同一个AppDelegate类中定义。我试过通过CFStreamClientContext结构传递指针：VoIP_TestViewController* testViewController = context->info;，我试图通过：[[UIApplication sharedApplication] delegate]访问主appDelegate，我尝试了通常的Obj-C和C结构（“这个“，”自我“，”超级“）。

非常感谢任何帮助！

Answer 1

确保将主应用代理头文件导入到需要调用它的视图中。
用它来调用它：

nameOfYourAppDelegate * appDelegate =（_ nameOfYourAppDelegate *）[[UIApplication sharedApplication] delegate];

//比你可以使用appDelegate做任何你想要的（即appDelegate.somView.someProperty）

Answer 2

啊，我是个白痴。我忘了导入成员类的类头（即我在尝试访问[ClassA.ClassB方法B]时忘记导入ClassB）。当然，XCode只提供了一个无法识别的选择器运行时错误，而不是一个缺少的声明编译器错误，使得调试比它本来应该更难。谢谢你！＃/ p>

如何在CFStream回调时访问应用程序的状态（类，属性等）？

2 个答案: