无法从nsmutableset添加或删除对象

检查一下:

- (IBAction)toggleFavorite {
    DataManager *data = [DataManager sharedDataManager];
    NSMutableSet *favorites = data.favorites;

    if (thisEvent.isFavorite == YES) {
        NSLog(@"Toggling off");
        thisEvent.isFavorite = NO;
        [favorites removeObject:thisEvent.guid];
        [favoriteIcon setImage:[UIImage imageNamed:@"notFavorite.png"] forState:UIControlStateNormal];
    }
    else {
        NSLog(@"Toggling on, adding %@", thisEvent.guid);
        thisEvent.isFavorite = YES;
        [favorites addObject:thisEvent.guid];
        [favoriteIcon setImage:[UIImage imageNamed:@"isFavorite.png"] forState:UIControlStateNormal];
    }
    NSLog(@"favorites array now contains %d members", [favorites count]);
}

这是从自定义ui按钮激发的。ui部分工作得很好——切换按钮使用的图像,我可以从其他东西看到thisevent.isFavoriteBool正在愉快地切换。我还可以在调试器中看到我正在获取数据管理器singleton。

但这是我的nslog:

2010-05-13 08:24:32.946 MyApp[924:207] Toggling on, adding 05db685f65e2
2010-05-13 08:24:32.947 MyApp[924:207] favorites array now contains 0 members
2010-05-13 08:24:33.666 MyApp[924:207] Toggling off
2010-05-13 08:24:33.666 MyApp[924:207] favorites array now contains 0 members
2010-05-13 08:24:34.060 MyApp[924:207] Toggling on, adding 05db685f65e2
2010-05-13 08:24:34.061 MyApp[924:207] favorites array now contains 0 members
2010-05-13 08:24:34.296 MyApp[924:207] Toggling off
2010-05-13 08:24:34.297 MyApp[924:207] favorites array now contains 0 members

最糟糕的是,这曾经奏效,我不知道我做了什么来打破它。

--编辑:根据请求,我的共享数据单件代码:

h

#import <Foundation/Foundation.h>

@interface DataManager : NSObject {
    NSMutableArray *eventList;
    NSMutableSet *favorites;
}

@property (nonatomic, retain) NSMutableArray *eventList;
@property (nonatomic, retain) NSMutableSet *favorites;

+(DataManager*)sharedDataManager;

@end

M:

#import "DataManager.h"

static DataManager *singletonDataManager = nil;

@implementation DataManager

@synthesize eventList;
@synthesize favorites;

+(DataManager*)sharedDataManager {
    @synchronized(self) {
        if (!singletonDataManager) {
            singletonDataManager = [[DataManager alloc] init];
        }
    }
    return singletonDataManager;
}

- (DataManager*)init {
    if (self = [super init]) {
        eventList = [[NSMutableArray alloc] init];
        favorites = [[NSMutableSet alloc] init];
    }
    return self;
}

------编辑编辑编辑------

在@techzen的建议下,我将访问方法移到了数据管理器singleton中。现在的情况如下:

#import "DataManager.h"

static DataManager *singletonDataManager = nil;

@implementation DataManager

@synthesize eventList;
@synthesize favorites;

+(DataManager*)sharedDataManager {
    @synchronized(self) {
        if (!singletonDataManager) {
            singletonDataManager = [[DataManager alloc] init];
        }
    }
    return singletonDataManager;
}

- (DataManager*)init {
    if (self = [super init]) {
        eventList = [[NSMutableArray alloc] init];
        favorites = [[NSMutableSet alloc] init];
    }
    return self;
}


#pragma mark -
#pragma mark Data management functions

- (void)addToFavorites:(NSString *)guid
{
    [self.favorites addObject:guid];
    NSLog(@"Item added--we now have %d faves.", [favorites count]);
}

- (void)removeFromFavorites:(NSString *)guid
{
    [favorites removeObject:guid];
    NSLog(!"Item removed--we now have %d faves.", [self.favorites count]);
}


@end

我让我的视图控制器在发生这种情况的地方调用 [[DataManager sharedManager] addToFavorites:Event.guid] 我没有将项目直接添加到收藏夹集本身,而是将日志记录的内容留在了原来的位置。

这是我的日志:

2010-05-13 13:25:52.396 EverWondr[8895:207] Toggling on, adding 05db685f65e2
2010-05-13 13:25:52.397 EverWondr[8895:207] Item added--we now have 0 faves.
2010-05-13 13:25:52.398 EverWondr[8895:207] favorites array now contains 0 members
2010-05-13 13:25:53.578 EverWondr[8895:207] Toggling off
2010-05-13 13:25:53.579 EverWondr[8895:207] favorites array now contains 0 members

所以…DataManager对象甚至不能向其自身属性添加任何内容!它不会像不可变类型那样抛出异常,它只是无声地失败了!

只是为了好玩,我把它改成了一个我更熟悉的非可变数组。相同的行为。