最初我认为这会起作用,但现在我明白它不会因为artistCollection是“Artist”对象的NSMutableArray.
@interface Artist : NSObject {
NSString *firName;
NSString *surName;
}
我的问题是,将“Artist”对象的NSMutableArray记录到磁盘的最佳方法是什么,以便我可以在下次运行应用程序时加载它们？
artistCollection = [[NSMutableArray alloc] init]; newArtist = [[Artist alloc] init]; [newArtist setFirName:objFirName]; [newArtist setSurName:objSurName]; [artistCollection addObject:newArtist]; NSLog(@"(*) - Save All"); [artistCollection writeToFile:@"/Users/Fgx/Desktop/stuff.txt" atomically:YES];
编辑
非常感谢,这是我最好的一件事.如果“Artist”包含其他对象(Applications)的NSMutableArray(softwareOwned)的额外实例变量,我将如何扩展编码以涵盖此内容？我会将NSCoding添加到“Applications”对象,然后在编码“Artist”之前对其进行编码,还是有办法在“Artist”中指定它？
@interface Artist : NSObject {
NSString *firName;
NSString *surName;
NSMutableArray *softwareOwned;
}
@interface Application : NSObject {
NSString *appName;
NSString *appVersion;
}
非常感谢
加里
解决方法
writeToFile：atomically：在Cocoa的集合类中仅适用于属性列表,即仅适用于包含标准对象(如NSString,NSNumber,其他集合等)的集合.
要详细说明jdelStrother’s answer,如果集合包含的所有对象都可以自行存档,则可以使用NSKeyedArchiver对集合进行存档.要为您的自定义类实现此功能,请使其符合NSCoding协议：
@interface Artist : NSObject <NSCoding> {
NSString *firName;
NSString *surName;
}
@end
@implementation Artist
static NSString *FirstNameArchiveKey = @"firstName";
static NSString *LastNameArchiveKey = @"lastName";
- (id)initWithCoder:(NSCoder *)decoder {
self = [super init];
if (self != nil) {
firName = [[decoder decodeObjectForKey:FirstNameArchiveKey] retain];
surName = [[decoder decodeObjectForKey:LastNameArchiveKey] retain];
}
return self;
}
- (void)encodeWithCoder:(NSCoder *)encoder {
[encoder encodeObject:firName forKey:FirstNameArchiveKey];
[encoder encodeObject:surName forKey:LastNameArchiveKey];
}
@end
有了这个,你可以编码集合：
NSData* artistData = [NSKeyedArchiver archivedDataWithRootObject:artistCollection]; [artistData writeToFile: @"/Users/Fgx/Desktop/stuff" atomically:YES];
