如何使用 NSKeyedArchiver 保存数据？

Question

嗨，我正在尝试从我创建的类中保存一个对象。它称为 shot，包含 5 个我希望保存的变量。这是 .h 文件 --- 它切断了 NSCoding 和 NSMutableCopying 协议以及我的导入，但它们就在那里。

#import <Foundation/Foundation.h>


@interface Shot : UIButton <NSCoding, NSMutableCopying> {

 int x;
 int y;
 int location;
 int quarter;
 bool made;

 int miss;
 int make;
}

@property()int x;

@property()int y;

@property()int location;

@property()int quarter;

@property()bool made;

-(void)set_x:(int)my_x set_y:(int)my_y set_quarter:(int)my_quarter set_made:(bool)my_made set_location:(int)my_location;

-(void)set_miss_AND_set_make;

@end

**Here are the methods I made to save the data in my .m file---**

-(void)encodeWithCoder:(NSCoder *)aCoder {

 [aCoder encodeInt:x forKey:@"x"];
 [aCoder encodeInt:y forKey:@"y"];
 [aCoder encodeInt:location forKey:@"location"];
 [aCoder encodeInt:quarter forKey:@"quarter"];
 [aCoder encodeBool:made forKey:@"made"];
}

-(id)initWithCoder:(NSCoder *)aDecoder {

 if (self = [super init]) {
 x = [aDecoder decodeIntForKey:@"x"];
 y = [aDecoder decodeIntForKey:@"y"];
 location = [aDecoder decodeIntForKey:@"location"];
 quarter = [aDecoder decodeIntForKey:@"quarter"];
 made = [aDecoder decodeBoolForKey:@"made"];
 }
 return self;
}

-(id)mutableCopyWithZone:(NSZone *)zone {

 Shot *newShot = [[Shot allocWithZone:zone]init];
 [newShot set_x:x set_y:y set_quarter:quarter set_made:made set_location:location];
 return newShot;
}

当我使用这些方法时，我似乎无法保存数据

-(NSString *)getPath {

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentFolder = [paths objectAtIndex:0];
 NSFileManager *fm = [[NSFileManager alloc]init];
 if ([fm fileExistsAtPath:documentFolder] == NO) {
  [fm createDirectoryAtPath:documentFolder withIntermediateDirectories:YES attributes:nil error:nil];
 }
 return [documentFolder stringByAppendingFormat:@"iStatTrackInfo.archive"];
}

-(void)saveData {

 NSString *path = [self getPath];
 [NSKeyedArchiver archiveRootObject:shotArray toFile:path];
}

-(void)loadData {

 NSString *path = [self getPath];
 NSFileManager *fm = [[NSFileManager alloc]init];
 if ([fm fileExistsAtPath:path] == YES) {
  shotArray = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
  return;
 }

 NSEnumerator *enumOne = [shotArray objectEnumerator];
 Shot *shotObject = [[Shot alloc]init];
 while (shotObject = [enumOne nextObject]) {
  Shot *shotShot = [[Shot alloc]init];
  shotShot = [shotObject mutableCopy];
  shotShot.frame = CGRectMake(0, 0, 50, 50);
  shotShot.backgroundColor = [UIColor whiteColor];
  [self addSubview:shotShot];
 }
}

我已将保存和加载方法设置为按钮，但我的数据仍然无法保存。请帮忙！！！

Answer 1

我终于解决了这个问题。除了上述帮助之外，.archive 不是一种文件类型。您无法保存 .archive，只能保存 .arch 或 .plist 这是我的主要问题。

Answer 2

首先，你像筛子一样泄漏内存。大量的alloc/init & mutableCopy，没有release。我建议阅读内存管理指南。

接下来，您的方法名称不遵循 Cocoa 约定。这些：

-(void)set_x:(int)my_x set_y:(int)my_y set_quarter:(int)my_quarter set_made:(bool)my_made set_location:(int)my_location;

-(void)set_miss_AND_set_make;

应该类似于：

-(void) resetMissAndMake; // or just missAndMake or activateMissAndMake
-(void) setX:(NSInteger)xValue y:(NSInteger)yValue quarter:(NSInteger)quarterValue location:(NSInteger)aLocation;

另外，getPath 应该只是 path。以 get 为前缀的方法非常罕见，并且具有非常特定的含义。

这也是无稽之谈：

 Shot *shotObject = [[Shot alloc]init];
 while (shotObject = [enumOne nextObject]) {
  Shot *shotShot = [[Shot alloc]init];
  shotShot = [shotObject mutableCopy];

不需要任何一个 [[Shot alloc]init] 调用（这些都是泄漏）。

最后，您的编码方法实施不正确。 正如文档所述，您需要根据需要调用super。

具体来说，您的 encodeWithCoder: 必须调用 super 的相同实现，并且 initWithCoder: 应该调用 super 的 initWithCoder:，而不是 init 。