通过 C++ 抽象层的 ARC Objective-C 委托

Question

我正在编写由 Objective-C 实现的简单跨平台 C++ 层 (dylib)。通过平台宏包含特定于平台的部分。

NSUserNotificationCenter 需要委托模式来处理特定操作，例如单击通知。我面临的问题是，只要我执行send，就会发送通知，但之后实例会立即卸载。因此，onclick 通知操作永远不会被调用 (didActivateNotification)，而是因为指针错误而崩溃。我怎样才能做到这一点？

注意： SomeObjectiveC.mm 是位于我的应用程序中的一个类。 AppleUserNotificationManager.m 由 NotificationManager+apple.mm 初始化，两者都位于我的 Dylib 中。

SomeObjectiveC.mm

Notification *notification = new Notification;
notification->setTitle("Foo bar notification");
notification->setMessage("Hello world!");

NotificationManager *notificationManager = new NotificationManager;
notificationManager->send(notification);

NotificationManager+apple.mm

#include "notificationManager+apple.hpp"

bool NotificationManager::send(Notification *notification)
{
    AppleUserNotificationManager *notificationManager = [[AppleUserNotificationManager alloc] init];

    NSString *title = [NSString stringWithUTF8String:notification->getTitle().c_str()];
    NSString *message = [NSString stringWithUTF8String:notification->getMessage().c_str()];
    if (notification->getSoundName().empty()) {
        [notificationManager sendWithTitle:title andMessage:message];
    }

    NSString *soundName = [NSString stringWithUTF8String:notification->getSoundName().c_str()];
    [notificationManager sendWithTitle:title andMessage:message andSound: soundName];

    return true;
}

AppleUserNotificationManager.m

#import "AppleUserNotificationManager.h"

@implementation AppleUserNotificationManager

@synthesize userNotification;

- (id)init
{
    [[NSUserNotificationCenter defaultUserNotificationCenter] setDelegate: self];
    userNotification = [[NSUserNotification alloc] init];

    self = [super init];
    return self;
}

/**
 *  @param NSUserNotificationCenter center
 *  @param NSUserNotification notification
 *
 *  @return bool
 */
- (BOOL)userNotificationCenter:(NSUserNotificationCenter *)center shouldPresentNotification:(NSUserNotification *)notification{
    return YES;
}

/**
 *  @param NSUserNotificationCenter center
 *  @param NSUserNotification notification
 */
- (void) userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification
{
    NSString *notificationText = [notification informativeText];
    NSString *urlRegEx = @"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";

    NSPredicate *urlTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", urlRegEx];
    if ([urlTest evaluateWithObject:notificationText]) {
        [[NSWorkspace sharedWorkspace] openURL:[NSURL URLWithString:notificationText]];
    }
}

/**
 * @param NSString title
 * @param NSString message
 * @param NSString soundName
 */
- (void)sendWithTitle:(NSString *)title andMessage:(NSString *)message andSound:(NSString *)soundName{
    userNotification.title = title;
    userNotification.informativeText = message;
    userNotification.soundName = soundName;

    [[NSUserNotificationCenter defaultUserNotificationCenter] deliverNotification: userNotification];
}

@end

Answer 1

分配前使用self指针？
下面的更改可以解决问题吗？

- (id)init
{
    self = [super init];

    [[NSUserNotificationCenter defaultUserNotificationCenter] setDelegate: self];
    userNotification = [[NSUserNotification alloc] init];

    return self;
}