Ich versuche, CoreTelephony-Benachrichtigungen über das (jetzt private) @ anzuhöreCTTelephonyCenterAddObserver C Funktion undCFNotificationCallback Rückrufsperren.

Meine Überbrückungskopfzeile (um die privaten C-Funktionen zu extern):

#include <CoreFoundation/CoreFoundation.h>

#if __cplusplus
extern "C" {
#endif

#pragma mark - API

    /* This API is a mimic of CFNotificationCenter. */

    CFNotificationCenterRef CTTelephonyCenterGetDefault();
    void CTTelephonyCenterAddObserver(CFNotificationCenterRef center, const void *observer, CFNotificationCallback callBack, CFStringRef name, const void *object, CFNotificationSuspensionBehavior suspensionBehavior);
    void CTTelephonyCenterRemoveObserver(CFNotificationCenterRef center, const void *observer, CFStringRef name, const void *object);
    void CTTelephonyCenterRemoveEveryObserver(CFNotificationCenterRef center, const void *observer);

    void CTIndicatorsGetSignalStrength(long int *raw, long int *graded, long int *bars);

#pragma mark - Definitions

    /* For use with the CoreTelephony notification system. */
    extern CFStringRef kCTIndicatorsSignalStrengthNotification;

#if __cplusplus
}
#endif

Mein Swift-Code:

let callback: CFNotificationCallback = { (center: CFNotificationCenter?, observer: UnsafeRawPointer?, name: CFString?, object: UnsafeRawPointer?, info: CFDictionary?) -> Void in
    // ...
}

CTTelephonyCenterAddObserver(CTTelephonyCenterGetDefault().takeUnretainedValue(), nil, callback, kCTIndicatorsSignalStrengthNotification.takeUnretainedValue(), nil, .coalesce)

Ich kann jedoch die Signatur meines @ nicht erhaltcompletion -Variable, um den Anforderungen des @ zu entsprechCFNotificationCallback typealias.

Cannot convert value of type
'(CFNotificationCenter?, UnsafeRawPointer?, CFString?, UnsafeRawPointer?, CFDictionary?) -> Void'
to specified type
'CFNotificationCallback' (aka '@convention(c) (Optional<CFNotificationCenter>, Optional<UnsafeMutableRawPointer>, Optional<CFNotificationName>, Optional<UnsafeRawPointer>, Optional<CFDictionary>) -> ()')

Wie bekomme ich@convention(c) Closures in Swift schön zu spielen?