我已经尝试了几个小时,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.
如果有意义的话,这就是数组:
- -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,turn;
等等
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;
- }
- - (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,这是问题所在:
设置一些断点后,在-saveGame的这一行之后会出现错误:
[NSKeyedArchiver archiveRootObject:savedGames toFile:[self dataFilePath]];
- 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: (
- 32339035,31077641,32720955,32290422,32143042,238843,25827,564412,342037,606848,17686,2733061,4646817,3140430,3149167,3144379,2837983,2746312,2773089,41684313,32123776,32119880,41678357,41678554,2777007,9884,9738
- )
如果重要,则从导航控制器中的UIBarButton调用-saveGame.
任何帮助表示赞赏,谢谢.
解决方法
这是错的:
- - (id)initWithCoder:(NSCoder *)coder {
- self = [[Piece alloc] init];
- if (self != nil)
- {
当initWithCoder:被调用时,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,否则你将不断地用脚射击.
此外,您的saveGame方法有几个问题.
>如果savedGames为nil,则表示您将对象而非数组保存到文件中.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unarchived数组上调用mutableCopy.
我完全不确定异常,但是修复了上述问题,要么它会消失,要么解决方案会变得更容易找到.