如何在Swift for iOS中正确使用CFNotificationCenterAddObserver

把我的头发拔出来让

cf通知中心添加观察者
在Swift中工作

        CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(),
        UnsafePointer<Void>(self),
        iosLocked,
        "com.apple.springboard.lockcomputer" as CFString,
        nil,
        CFNotificationSuspensionBehavior.DeliverImmediately)

我也试着按照建议连接到objc，但没有成功

这是我的桥：

LockNotifierCallback.h：

#import <Foundation/Foundation.h>

@interface LockNotifierCallback : NSObject

+ (void(*)(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo))notifierProc;

@end

使用更新的CFNotificationCenterAddObserver调用，如下所示：

CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(),
        LockNotifierCallback.notifierProc,
        iosLocked,
        "com.apple.springboard.lockcomputer" as CFString,
        nil,
        CFNotificationSuspensionBehavior.DeliverImmediately)

当然，LockNotifierCallback.h在我的桥接头中。错误继续：

Cannot convert the expression's type '(CFNotificationCenter!, () -> CFunctionPointer<((CFNotificationCenter!, UnsafeMutablePointer<Void>, CFString!, UnsafePointer<Void>, CFDictionary!) -> Void)>, () -> (), CFString, NilLiteralConvertible, CFNotificationSuspensionBehavior)' to type 'StringLiteralConvertible'

无法将表达式的类型“（CFNotificationCenter！，（）->cfFunctionPointer Void）>，（）->（），CFString，NilLiteralConverable，CFNotificationSuspensionBehavior）转换为类型“StringLiteralConverable”
我在DarwinNotifications方面遇到一些问题，您可以尝试使用此包装器类
只需在桥接文件中包含头文件。你可以在swift中使用它

DarwinNotificationsManager.h：

#import <Foundation/Foundation.h>

#ifndef DarwinNotifications_h
#define DarwinNotifications_h

@interface DarwinNotificationsManager : NSObject

@property (strong, nonatomic) id someProperty;

+ (instancetype)sharedInstance;

- (void)registerForNotificationName:(NSString *)name callback:(void (^)(void))callback;
- (void)postNotificationWithName:(NSString *)name;

@end

#endif

我写这篇文章是为了将一个通知从共享扩展传递到它的父应用程序，当在iPadOS中时，两者都可以同时激活

它们被放置在应用程序和扩展共享的库中。应用程序使用ExtensionListener，扩展程序使用ExtensionEvent

final public class ExtensionListener: NSObject {

    // the inter-process NotificationCenter
    private let center = CFNotificationCenterGetDarwinNotifyCenter()
    private var listenersStarted = false
    fileprivate static let notificationName = "com.example.CrossProcessExtensionAction" as CFString

    public override init() {
        super.init()
        // listen for an action in the Share Extension
        startListeners()
    }

    deinit {
        // don't listen anymore
        stopListeners()
    }

    //    MARK: listening
    fileprivate func startListeners() {
        if !listenersStarted {
            self.listenersStarted = true
            CFNotificationCenterAddObserver(center, Unmanaged.passRetained(self).toOpaque(), { (center, observer, name, object, userInfo) in
                // send the equivalent internal notification
                NotificationCenter.default.post(name: NSNotification.Name.SomeInternalExtensionAction, object: nil)
            }, Self.notificationName, nil, .deliverImmediately)
        }
    }

    fileprivate func stopListeners() {
        if listenersStarted {
            CFNotificationCenterRemoveEveryObserver(center, Unmanaged.passRetained(self).toOpaque())
            listenersStarted = false
        }
    }
}

final public class ExtensionEvent: NSObject {
    public static func post() {
        CFNotificationCenterPostNotification(CFNotificationCenterGetDarwinNotifyCenter(), CFNotificationName(rawValue: ExtensionListener.notificationName), nil, nil, true)
    }
}

CFNotificationCenterAddObserver
获取一个
cffunctionpointer
，您无法真正从Swift创建它（请参阅）。你可以通过做一些类似于这样的Objective-C桥接来解决这个问题：谢谢Mark，但是为什么它会在ios文档中以swift声明的形式出现呢？您仍然可以从Swift使用它，您只需将C或Objective-C中定义的函数传递给它，而不是Swift闭包函数。再次感谢Mark。我仍然被卡住了，请参见上面编辑的Q。我不确定什么是
iosLocked
，但看起来您只是把参数放错了位置。这为我编译：
CFNotificationCenterAddObserver（CFNotificationCenterGetDarwinNotifyCenter（），nil，LockNotifierCallback.notifierProc（），“com.apple.springboard.lockcomputer”，nil，CFNotificationSuspensionBehavior.Delivery立即）
如果启用后台应用程序刷新，收到darwin通知后，应用程序是否会从后台醒来，执行一些与远程通知类似的代码？保持电源按钮的“YourNotificationName”是什么。如何通过
CFNotificationCenterPostNotification
中的
String
消息？我的问题已结束，请参阅
#import <Foundation/Foundation.h>

#ifndef DarwinNotifications_h
#define DarwinNotifications_h

@interface DarwinNotificationsManager : NSObject

@property (strong, nonatomic) id someProperty;

+ (instancetype)sharedInstance;

- (void)registerForNotificationName:(NSString *)name callback:(void (^)(void))callback;
- (void)postNotificationWithName:(NSString *)name;

@end

#endif

#import <Foundation/Foundation.h>
#import "DarwinNotificationsManager.h"


@implementation DarwinNotificationsManager {
    NSMutableDictionary * handlers;
}

+ (instancetype)sharedInstance {
    static id instance = NULL;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[self alloc] init];
    });
    return instance;
}

- (instancetype)init {
    self = [super init];
    if (self) {
        handlers = [NSMutableDictionary dictionary];
    }
    return self;
}

- (void)registerForNotificationName:(NSString *)name callback:(void (^)(void))callback {
    handlers[name] = callback;
    CFNotificationCenterRef center = CFNotificationCenterGetDarwinNotifyCenter();
    CFNotificationCenterAddObserver(center, (__bridge const void *)(self), defaultNotificationCallback, (__bridge CFStringRef)name, NULL, CFNotificationSuspensionBehaviorDeliverImmediately);
}

- (void)postNotificationWithName:(NSString *)name {
    CFNotificationCenterRef center = CFNotificationCenterGetDarwinNotifyCenter();
    CFNotificationCenterPostNotification(center, (__bridge CFStringRef)name, NULL, NULL, YES);
}

- (void)notificationCallbackReceivedWithName:(NSString *)name {
    void (^callback)(void) = handlers[name];
    callback();
}

void defaultNotificationCallback (CFNotificationCenterRef center,
                 void *observer,
                 CFStringRef name,
                 const void *object,
                 CFDictionaryRef userInfo)
{
    NSLog(@"name: %@", name);
    NSLog(@"userinfo: %@", userInfo);

    NSString *identifier = (__bridge NSString *)name;
    [[DarwinNotificationsManager sharedInstance] notificationCallbackReceivedWithName:identifier];
}


- (void)dealloc {
    CFNotificationCenterRef center = CFNotificationCenterGetDarwinNotifyCenter();
    CFNotificationCenterRemoveEveryObserver(center, (__bridge const void *)(self));
}


@end

let darwinNotificationCenter = DarwinNotificationsManager.sharedInstance()
darwinNotificationCenter.registerForNotificationName("YourNotificationName"){
            //code to execute on notification
}

final public class ExtensionListener: NSObject {

    // the inter-process NotificationCenter
    private let center = CFNotificationCenterGetDarwinNotifyCenter()
    private var listenersStarted = false
    fileprivate static let notificationName = "com.example.CrossProcessExtensionAction" as CFString

    public override init() {
        super.init()
        // listen for an action in the Share Extension
        startListeners()
    }

    deinit {
        // don't listen anymore
        stopListeners()
    }

    //    MARK: listening
    fileprivate func startListeners() {
        if !listenersStarted {
            self.listenersStarted = true
            CFNotificationCenterAddObserver(center, Unmanaged.passRetained(self).toOpaque(), { (center, observer, name, object, userInfo) in
                // send the equivalent internal notification
                NotificationCenter.default.post(name: NSNotification.Name.SomeInternalExtensionAction, object: nil)
            }, Self.notificationName, nil, .deliverImmediately)
        }
    }

    fileprivate func stopListeners() {
        if listenersStarted {
            CFNotificationCenterRemoveEveryObserver(center, Unmanaged.passRetained(self).toOpaque())
            listenersStarted = false
        }
    }
}

final public class ExtensionEvent: NSObject {
    public static func post() {
        CFNotificationCenterPostNotification(CFNotificationCenterGetDarwinNotifyCenter(), CFNotificationName(rawValue: ExtensionListener.notificationName), nil, nil, true)
    }
}