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标题: ios - NSMutableDictionary setObject :forKey (ios 6 without ARC) results in NULL [打印本页]

作者: 菜鸟教程小白 时间: 2022-12-12 23:51
标题: ios - NSMutableDictionary setObject :forKey (ios 6 without ARC) results in NULL

以下代码在升级到 iOS 6 之前可以运行。它也可以在 5.1 iPhone 模拟器中运行，但在 6.0 模拟器和设备上会失败。

尝试在 NSMutableDictionary 的循环中设置对象:forKey。已尝试在循环中添加(如下面的代码所示)，并尝试使用对象和键的数组进行初始化，这会导致相同的失败。另一个奇怪的信息是，有时它有效，但大部分时间都失败了。添加的对象是 UILocalNotification，键是表示 WeekDay 的对象(不仅仅是一个简单的字符串)。运行的输出如下图所示。 UILocalNotifications 和键显然不是 NULL，但 MutableDictionary 中添加的对在大多数情况下对于某些对象具有 NULL。大多数情况下，它是最后添加的日期(键)，其对象为空。我完全不知道这是如何破坏的，在此先感谢您的帮助!

WeekDay 的复制方法(NSCopying 协议(protocol)):

- (id)copyWithZoneNSZone *)zone
{
    WeekDay * copy = [[WeekDay alloc] initWithDay:self.day];
    return copy;
}

使用 setObject:forKey: 的代码片段

NSMutableDictionary * newAlarmsDictionary = [[NSMutableDictionary alloc] init];
NSArray * theDayKeys = [[_daysEnabledDict allKeys] sortedArrayUsingSelectorselector(compare];

NSMutableArray * tempNotifyArray = [[NSMutableArray alloc] init];
UILocalNotification * theAlarm = nil;
WeekDay * theWeekDay = nil;

for (int i=0; i < [theDayKeys count]; i++) {

    if ([[_daysEnabledDict objectForKey:[theDayKeys objectAtIndex:i]] boolValue] == TRUE) {

        theWeekDay = [theDayKeys objectAtIndex:i];

        NSDate * now = [NSDate date];

... deleted lines setting up fire date for UILocalNotification, not significant to problem ...

        theAlarm = [[UILocalNotification alloc] init];
        theAlarm.fireDate = itemDate;
        theAlarm.repeatInterval = NSWeekCalendarUnit;
        theAlarm.timeZone = [NSTimeZone localTimeZone];
        theAlarm.soundName = UILocalNotificationDefaultSoundName;
        theAlarm.applicationIconBadgeNumber = 0;

        [newAlarmsDictionary setObject:theAlarm forKey:theWeekDay];
        [tempNotifyArray addObject:theAlarm];
        [theAlarm release];
        }
    }
}
NSLog(@"--Debug: tempNotifyArray---- %@ -------------", tempNotifyArray);
NSLog(@"--Debug: newAlarmsDictionary ====== %@ =============", newAlarmsDictionary);

这是代码片段末尾的两个 NSlog 语句的输出。这个特殊的运行增加了 4 个通知，从周三到周六。放入 tempNotifyArray 的“警报”是有效的，但在添加到字典时(在本例中为一个)为空。

2012-11-26 11:07:01.087 MedTrack[9728:11303] --Debug: tempNotifyArray---- (

"<UIConcreteLocalNotification: 0x7277940>{fire date = Wednesday, November 28, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Wednesday, November 28, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}",


"<UIConcreteLocalNotification: 0x8883280>{fire date = Thursday, November 29, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Thursday, November 29, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}",


"<UIConcreteLocalNotification: 0x75c6590>{fire date = Friday, November 30, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Friday, November 30, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}",


"<UIConcreteLocalNotification: 0x75c83e0>{fire date = Saturday, December 1, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Saturday, December 1, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}"

) -------------

2012-11-26 11:07:01.097 MedTrack[9728:11303] --Debug: newAlarmsDictionary ====== {


"[WeekDay] 6 (Sat)" = (null);


"[WeekDay] 3 (Wed)" = "<UIConcreteLocalNotification: 0x7277940>{fire date = Wednesday, November 28, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Wednesday, November 28, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}";


"[WeekDay] 4 (Thu)" = "<UIConcreteLocalNotification: 0x8883280>{fire date = Thursday, November 29, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Thursday, November 29, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}";


"[WeekDay] 5 (Fri)" = "<UIConcreteLocalNotification: 0x75c6590>{fire date = Friday, November 30, 2012, 11:06:00 AM Eastern Standard Time, time zone = America/Toronto (EST) offset -18000, repeat interval = NSWeekCalendarUnit, repeat count = UILocalNotificationInfiniteRepeatCount, next fire date = Friday, November 30, 2012, 11:06:00 AM Eastern Standard Time, user info = {\n    Temp = Fred;\n}}";

Best Answer-推荐答案

这里的问题是你实现了-copyWithZone:，但是你没有实现-isEqual:。在不了解对象的完整结构的情况下，我无法回答应该如何实现，但这里有一个很好的基础:

- (BOOL)isEqualid)otherObject; { if ([otherObject isKindOfClass:[self class]]) { WeekDay *otherWeekDay= (WeekDay *)otherObject; if (self.day != [otherWeekDay day]) return NO; if (self.name != [otherWeekDay name]) return NO; return YES; } return NO; } - (NSUInteger) hash; { return self.day ^ [self.name hash]; }

关于ios - NSMutableDictionary setObject :forKey (ios 6 without ARC) results in NULL，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13568682/

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