Question

我已经尝试了几个小时，但我无法解决这个问题。

我正在制作一个可以保存未完成的国际象棋游戏的应用程序，所以我正在尝试将数组写入文件。

这就是数组的含义，如果有意义的话：

-NSMutableArray savedGames
--GameSave a
---NSMutableArray board;
----Piece a, b, c, etc.
-----some ints
---NSString whitePlayer, blackPlayer;
---int playerOnTop, turn;
--GameSave b
---NSMutableArray board;
----Piece a, b, c, etc.
-----some ints
---NSString whitePlayer, blackPlayer;
---int playerOnTop, turn;

等

这些是我的NSCoding方法：

GameSave.m

- (void)encodeWithCoder:(NSCoder *)coder {
    [coder encodeObject:whitePlayer forKey:@"whitePlayer"];
    [coder encodeObject:blackPlayer forKey:@"blackPlayer"];
    [coder encodeInt:playerOnTop forKey:@"playerOnTop"];
    [coder encodeInt:turn forKey:@"turn"];
    [coder encodeObject:board forKey:@"board"];
}

- (id)initWithCoder:(NSCoder *)coder {
    self = [[GameSave alloc] init];
    if (self != nil)
    {
        board = [coder decodeObjectForKey:@"board"];
        whitePlayer = [coder decodeObjectForKey:@"whitePlayer"];
        blackPlayer = [coder decodeObjectForKey:@"blackPlayer"];
        playerOnTop = [coder decodeIntForKey:@"playerOnTop"];
        turn = [coder decodeIntForKey:@"turn"];
    }   
    return self;
}

Piece.m

- (void)encodeWithCoder:(NSCoder *)coder {
    [coder encodeInt:color forKey:@"color"];
    [coder encodeInt:piece forKey:@"piece"];
    [coder encodeInt:row forKey:@"row"];
    [coder encodeInt:column forKey:@"column"];
}

- (id)initWithCoder:(NSCoder *)coder {
    self = [[Piece alloc] init];
    if (self != nil)
    {
        color = [coder decodeIntForKey:@"color"];
        piece = [coder decodeIntForKey:@"piece"];
        row = [coder decodeIntForKey:@"row"];
        column = [coder decodeIntForKey:@"column"];
    }   
    return self;
}

这是试图存档并保存到文件的代码：

- (void)saveGame {
    ChessSaverAppDelegate *delegate = (ChessSaverAppDelegate *) [[UIApplication sharedApplication] delegate];
    [[delegate gameSave] setBoard:board];

    NSMutableArray *savedGames = [NSKeyedUnarchiver unarchiveObjectWithFile:[self dataFilePath]];
    if (savedGames == nil) {
        [NSKeyedArchiver archiveRootObject:[delegate gameSave] toFile:[self dataFilePath]];
    } else {
        [savedGames addObject:[delegate gameSave]];
        [NSKeyedArchiver archiveRootObject:savedGames toFile:[self dataFilePath]];
    }
}

- (NSString *)dataFilePath {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    return [documentsDirectory stringByAppendingPathComponent:@"gameSaves.plist"];
}

对不起，问题出在这里：

设置一些断点后，从-saveGame这一行后出现错误：
[NSKeyedArchiver archiveRootObject：savedGames toFile：[self dataFilePath]];

这就是控制台中显示的内容：

2010-05-11 17:04:08.852 ChessSaver[62065:207] *** -[NSCFType encodeWithCoder:]: unrecognized selector sent to instance 0x3d3cd30
2010-05-11 17:04:08.891 ChessSaver[62065:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFType encodeWithCoder:]: unrecognized selector sent to instance 0x3d3cd30'
2010-05-11 17:04:08.908 ChessSaver[62065:207] Stack: (
    32339035,
    31077641,
    32720955,
    32290422,
    32143042,
    238843,
    25827,
    238843,
    564412,
    342037,
    238843,
    606848,
    17686,
    2733061,
    4646817,
    2733061,
    3140430,
    3149167,
    3144379,
    2837983,
    2746312,
    2773089,
    41684313,
    32123776,
    32119880,
    41678357,
    41678554,
    2777007,
    9884,
    9738
)

如果重要，则从导航控制器中的UIBarButton调用-saveGame。

感谢任何帮助，谢谢。

Answer 1

这是错误的：

- (id)initWithCoder:(NSCoder *)coder {
    self = [[Piece alloc] init];
    if (self != nil)
    {

当调用initWithCoder:时，已经分配了类的实例。在您的代码中，您正在泄漏该实例。你应该这样做：

- (id)initWithCoder:(NSCoder *)coder {
    self = [super init]; // or [self init] if needed
    if (self != nil)
    {

此外，当您解码对象时，您不拥有它，因此您需要保留它。

board = [[coder decodeObjectForKey:@"board"] retain];

如果你没有“获得”保留/释放规则，现在就学习它们，否则你将不断地射击自己。

此外，您的saveGame方法存在一些问题。

如果savedGames为nil，则表示您正在将对象而不是数组保存到文件中。这意味着在下次运行时，未归档的对象将不是您期望的数组。
未归档的数组是不可变的。将类型声明为NSMutableArray并不重要，如果归档可变数组，则将在unarchive上获得不可变数组。如果要修改它，则需要在未归档的数组上调用mutableCopy。

我确实不确定异常，但是修复了上述问题，要么它会消失，要么解决方案会更容易找到。

Answer 2

如果你无法使你的NSKeyedArchiver工作，也许另一种选择是writeToFile：

- (NSString *) saveFilePath:(NSString*)fileName {
 NSArray *saveFilePathArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *filePath = [[NSString alloc] initWithFormat:@"%@.extension", fileName];
 return [[saveFilePathArray objectAtIndex:0] stringByAppendingPathComponent:filePath];
 [saveFilePathArray release];
 [filePath release];
}

 ...
 NSMutableArray *yourUnsavedGameObject = [[NSMutableArray alloc] initWithArray:yourUnsavedGame];
 // Write the dictionary to a file
 [yourUnsavedGameObject writeToFile:[self saveFilePath] atomically:YES];
 ...

iPhone - 归档自定义对象数组

2 个答案: