Question

我创建了一个简单的plist文件，其中包含我正在编写的纸牌游戏的一些用户偏好。我还创建了一个控制器，读取和写入这个plinger文件，这是一个singelton。一切正常，但经过几次尝试，它停止工作。将值记录到控制台，它会显示返回值为0的列表，这会导致我的应用程序崩溃我已经删除了plist并创建了一个新的，然后相同的故事，工作正常2或3次然后繁荣零。

这里是控制器singelton代码的副本：

@implementation userOptionsController

static userOptionsController* _sharedOptionsController = nil;
@synthesize backgroundSound=_backgroundSound;
@synthesize soundEffects = _soundEffects;
@synthesize coach = _coach;
@synthesize numberOfDecks = _numberOfDecks ;

+(userOptionsController*)sharedOptionsController{

@synchronized([userOptionsController class])
{
    if(!_sharedOptionsController)

        [[self alloc]init];
    return _sharedOptionsController;
}
return nil;
}

+(id)alloc
{
@synchronized ([userOptionsController class])
{
    NSAssert(_sharedOptionsController == nil, @"Attempted to allocate a second instance of      userOptionsController singleton");
    _sharedOptionsController = [super alloc];
    return _sharedOptionsController;
}
return nil;
}


- (id) init {

self = [super init];
if (self) {

    }
return self;
 }

-(void)readPlistFile
{
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,   NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"playerPrefOptions.plist"]; 

NSFileManager *fileManager = [NSFileManager defaultManager];

if (![fileManager fileExistsAtPath: path]) 
{
    NSString *bundle = [[NSBundle mainBundle] pathForResource:@"playerPrefOptions" ofType:@"plist"];

    [fileManager copyItemAtPath:bundle toPath: path error:&error]; 
}
NSMutableDictionary *temp = [[NSMutableDictionary alloc] initWithContentsOfFile: path];
self.backgroundSound = [[temp objectForKey:@"backgroundSounds"]boolValue];
self.soundEffects = [[temp objectForKey:@"soundEffects"]boolValue];
self.coach =[[temp objectForKey:@"coach"]boolValue];
self.numberOfDecks = [[temp objectForKey:@"numberOfDecks"]intValue];
}

-(void)writeOptionsToFile
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"playerPrefOptions.plist"];

NSMutableDictionary *infoDict = [[NSMutableDictionary alloc] initWithContentsOfFile: path];

NSNumber *moshe = [NSNumber numberWithInt:self.numberOfDecks];

[infoDict setObject: moshe forKey:@"numberOfDecks"];
[infoDict setObject:[NSNumber numberWithBool:self.coach] forKey:@"coach"];
[infoDict setObject:[NSNumber numberWithBool:self.backgroundSound]   forKey:@"backgroundSounds"];
[infoDict setObject:[NSNumber numberWithBool:self.soundEffects] forKey:@"soundEffects"];
[infoDict writeToFile:path atomically:YES];

}

@end

所以财产：

int numberOfDecks =[userOptionsController sharedOptionsController].numberOfDecks;

将返回零。

任何想法？

感谢。

Answer 1

与其使用plist代替此内容，看起来NSUserDefaults是更合适的位置。

而不是使用默认的plist文件发送应用，而只使用registerDefaults:发送NSUserDefaults（通常在您的应用代理application:didFinishLaunchingWithOptions:中完成）。

然后，无论何时进行任何更改，只需更新NSUserDefaults并致电synchronize以保存更改。

Answer 2

试试这个，看看它做了什么（输出了什么日志）：

@implementation userOptionsController

+ (userOptionsController*)sharedOptionsController
{
    static dispatch_once_t pred = 0;
    __strong static id _sharedObject = nil;
    dispatch_once(&pred, ^{
        _sharedObject = [[self alloc] init];
    });

    return _sharedObject;
}

- (id) init {

    self = [super init];
    if (self) {

    }

    return self;
}

-(void)readPlistFile
{
    NSError *error;
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,   NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"playerPrefOptions.plist"];

    NSFileManager *fileManager = [NSFileManager defaultManager];

    if (![fileManager fileExistsAtPath: path])
    {
        NSString *bundle = [[NSBundle mainBundle] pathForResource:@"playerPrefOptions" ofType:@"plist"];

        if (![fileManager copyItemAtPath:bundle toPath: path error:&error]) {
            NSLog(@"ERROR - file couldn't be copied: %@", error);
        }
    }

    NSMutableDictionary *temp = [[NSMutableDictionary alloc] initWithContentsOfFile: path];

    if (temp == nil) {
        NSLog(@"ERROR - file couldn't be read");
    }

    self.backgroundSound = [[temp objectForKey:@"backgroundSounds"]boolValue];
    self.soundEffects = [[temp objectForKey:@"soundEffects"]boolValue];
    self.coach =[[temp objectForKey:@"coach"]boolValue];
    self.numberOfDecks = [[temp objectForKey:@"numberOfDecks"]intValue];
}

-(void)writeOptionsToFile
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"playerPrefOptions.plist"];

    NSMutableDictionary *infoDict = [[NSMutableDictionary alloc] initWithContentsOfFile: path];

    NSNumber *moshe = [NSNumber numberWithInt:self.numberOfDecks];

    [infoDict setObject: moshe forKey:@"numberOfDecks"];
    [infoDict setObject:[NSNumber numberWithBool:self.coach] forKey:@"coach"];
    [infoDict setObject:[NSNumber numberWithBool:self.backgroundSound]   forKey:@"backgroundSounds"];
    [infoDict setObject:[NSNumber numberWithBool:self.soundEffects] forKey:@"soundEffects"];

    if (![infoDict writeToFile:path atomically:YES]) {
        NSLog(@"ERROR - failed to write the new file (%@)", path);
    } else {
        NSLog(@"Completed write of:\n%@", infoDict);
    }
}

@end

从plist文件中读取的问题

2 个答案: