Objective-C NSUserDefaults：HighScoreManager，为什么这不起作用？

Question

我的应用程序不会保存数据或加载数据，它只会崩溃，我想知道我在高分管理器课程中做错了什么。

我将发布我班级的 .h 和 .m 文件：

.h

#import <Foundation/Foundation.h>

@interface Score : NSObject
{
    NSString *name;
    NSNumber *score;
}

@property (assign, nonatomic) NSString *name;
@property (assign, nonatomic) NSNumber *score;

+ (Score *) score: (NSNumber *)score_ name: (NSString *)name_;
- (id) initWithScore: (NSNumber *)score_ name: (NSString *)name_;

@end

@interface HighScoreManager : NSObject
{
    NSArray *an_;
    NSArray *as_;
    BOOL loaded;
}

- (void) load;
- (BOOL) noScores;
- (NSArray *) sortedScores;
- (void) add: (NSString *)name score: (NSNumber *)score;

@end

.m

#import "HighScoreManager.h"

@implementation Score
@synthesize name, score;

+ (Score *) score: (NSNumber *)score_ name: (NSString *)name_
{
    return [[[Score alloc] initWithScore: score_ name: name_] autorelease];
}

- (id) initWithScore: (NSNumber *)score_ name: (NSString *)name_
{
    if((self = [super init]))
    {
        score = score_;
        name = name_;
    }

    return self;
}

@end

@implementation HighScoreManager

- (id) init
{
    if((self = [super init]))
    {
        loaded = NO;
    }

    return self;
}

- (void) load
{
    if(!loaded) {
        NSUserDefaults *NSUD = [NSUserDefaults standardUserDefaults];
        [NSUD synchronize];
        an_ = [NSUD arrayForKey: @"game.score.names"];
        as_ = [NSUD arrayForKey: @"game.score.scores"];
        [NSUD release];

        loaded = YES;
    }
}

- (BOOL) noScores
{
    [self load];
    return [an_ count] < 1;
}

- (NSArray *) sortedScores
{
    [self load];
    NSMutableArray *scoresObj = [NSMutableArray array];

    for(NSUInteger i = 0; i < [an_ count]; i++)
    {
        [scoresObj addObject: [Score score: [as_ objectAtIndex: i] name: [an_ objectAtIndex: i]]];
    }

    NSSortDescriptor *sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@"score" ascending: NO] autorelease];
    NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];

    return [scoresObj sortedArrayUsingDescriptors: sortDescriptors];
}

- (void) add: (NSString *)name score: (NSNumber *)score
{
    NSUserDefaults *NSUD2 = [NSUserDefaults standardUserDefaults];
    [NSUD2 setObject: [[NSUD2 arrayForKey: @"game.score.names"] arrayByAddingObject: name] forKey: @"game.score.names"];
    [NSUD2 setObject: [[NSUD2 arrayForKey: @"game.score.scores"] arrayByAddingObject: score] forKey: @"game.score.scores"];
    [NSUD2 synchronize];
}

- (void) dealloc
{
    [an_ release];
    [as_ release];
    [super dealloc];
}

@end

我如何尝试使用该类

    HighScoreManager *HSM1 = [HighScoreManager new];
    [HSM1 add: @"Johannes" score: [NSNumber numberWithInt: 1298]];
    [HSM1 add: @"Johannes" score: [NSNumber numberWithInt: 8723]];
    [HSM1 add: @"Johannes" score: [NSNumber numberWithInt: 3283]];
    [HSM1 add: @"Johannes" score: [NSNumber numberWithInt: 1763]];
    [HSM1 add: @"Johannes" score: [NSNumber numberWithInt: 9931]];

    HighScoreManager *HSM = [HighScoreManager new];

    // Check if there even are any high scores.
    if([HSM noScores])
    {
        CCLabel *noScoresYet = [CCLabel labelWithString: @"There are no scores yet." fontName: @"Helvetica" fontSize: 36];
        noScoresYet.position = ccp(win.width / 2, win.height / 2);
        [noScoresYet setColor: ccc3(0, 0, 0)];
        [self addChild: noScoresYet];
    } else
    {
        // Oh look, there were some high scores!

    }

    [HSM release];

即使我“保存”了分数，但当我离开“分数”页面并返回时，应用程序就会崩溃。我不确定我做错了什么或为什么没有保存

---

当它崩溃“_class_getMethodNoSuper_nolock”，有时是 objC_send 或类似的东西时，我会得到这个

Answer 1

• 不要释放NSUD。你没有创造它，也没有保留它，所以你不拥有它。这可能会导致崩溃。

• 您还应该保留实例变量。

• [NSUD2 arrayForKey: @"game.score.names"] 会在开头返回 nil，所以 [[NSUD2 arrayForKey: @"game.score.names"] arrayByAddingObject: name] 也将是 nil。您总是将字典值设置为 nil。

• （并避免使用“an_”之类的变量名。这会使您的代码难以阅读。）

Answer 2

准确描述崩溃发生的位置，也许我可以提供更多帮助。我发现了至少一个问题：

return [[[self alloc] initWithScore: score_ name: name_] autorelease];

应该是

return [[[Score alloc] initWithScore: score_ name: name_] autorelease];

Answer 3

没有测试您的代码，但我注意到的第一件事是您的静态工厂方法，它尝试分配 self 而不是类 Score

我很确定你需要：

+ (Score *) score: (NSNumber *)score_ name: (NSString *)name_
{
     return [[[Score alloc] initWithScore: score_ name: name_] autorelease];
}

还有一件事。您在 Score 类中的属性被声明为 assign，这意味着您不会保留您获得的分数和名称，如果它们超出范围也会导致您的应用崩溃。