子类化NSObject时出错：“ EXC_BAD_ACCESS”

问题描述

| 我正在尝试创建一个名为HighscoresController的类，该类将NSObject子类化。当我以下列方式调用

init

方法时，调试器

GDB: Program received signal: \"EXC_BAD_ACCESS\"

出现错误。有谁知道为什么吗？我完全陷入了困境。

// Initialize the highscores controller
_highscoresController = [[HighscoresController alloc] init];

这是我的课程实现：

#import \"HighscoresController.h\"
#import \"Constants.h\"

@implementation HighscoresController

@synthesize highscoresList = _highscoresList;

- (id) init {

    self = [super init];

    _highscoresList = [[NSMutableArray alloc] initWithCapacity:kHighscoresListLength];
    int kMyListNumber = 0;

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    Nsstring *documentsDirectory = [paths objectAtIndex:0];
    Nsstring *filePath = [documentsDirectory stringByAppendingPathComponent:@\"highscores.plist\"];

    if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) { // if settings file exists
        NSArray *HighscoreslistofLists = [[NSArray alloc] initWithContentsOfFile:filePath];
        _highscoresList = [HighscoreslistofLists objectAtIndex:kMyListNumber];
        [HighscoreslistofLists release];
    } else { // if no highscores file,create a new one
        NSMutableArray *array = [[NSMutableArray alloc] init];
        [array addobject:_highscoresList];
        [array writetoFile:filePath atomically:YES];
        [array release];
    }
    [_highscoresList addobject:[NSNumber numberWithFloat:0.0f]];

    return self;    
}

- (void) addscore:(float)score {
    // Implementation
}

- (BOOL) isscore:(float)score1 betterThan:(float)score2 {
    if (score1 > score2)
        return true;
    else
        return false;
}

- (BOOL) checkscoreAndAddToHighscoresList:(float)score {
    NSLog(@\"%d\",[_highscoresList count]);
    if ([_highscoresList count] < kHighscoresListLength) {

        [self addscore:score];
        [self saveHighscoresList];
        return true;

    } else {

        NSNumber *lowscoreNumber = [_highscoresList objectAtIndex:[_highscoresList count]-1];
        float lowscore = [lowscoreNumber floatValue];
        if ([self isscore:score betterThan:lowscore]) {

            [self addscore:score];
            [self saveHighscoresList];
            return true;

        }

    }

    return false;

}

- (void) saveHighscoresList {
    // Implementation
}

- (void) dealloc {
    [_highscoresList release];
    _highscoresList = nil;
    [super dealloc];
}

@end

解决方法

这行有两个问题：

_highscoresList = [HighscoresListOfLists objectAtIndex:kMyListNumber];

您将丢失对该方法前面分配的数组的引用-内存泄漏。 您将其替换为对您不保留的对象的引用。在释放对象之后使用此方法肯定会导致您的错误访问异常。