)
在我想使用 NSUserDefaults
保存之前,我的 NSObject
未正确编码
。
这是我的代码:
NSUserDefaults *userDefault=[NSUserDefaults standardUserDefaults];
NSLog(@"Favorite artists before encode: %@", self.model.favoriteArtists);
NSData *myEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:self.model];
[userDefault setObject:myEncodedObject forKey:[NSString stringWithFormat:@"Favorites"]];
[userDefault synchronize];
NSData *myDecodedObject = [userDefault objectForKey: [NSString stringWithFormat:@"Favorites"]];
self.model=[NSKeyedUnarchiver unarchiveObjectWithData: myDecodedObject];
NSLog(@"Favorite artists after encode: %@",self.model.favoriteArtists);
编码前控制台的输出是这样的:
Favorite artists before encode: (
"<SBQArtistModel: 0x15671d30>"
)
编码后控制台的输出:
Favorite artists after encode: (
)
为什么没有保存任何内容?
我真的被这个问题困扰了。代码看起来是正确的,但我不明白发生了什么。
谢谢
编辑
我正在我的 NSObject
类中实现 NSCoding
协议(protocol)并实现 initWithCoder:
和 encodeWithCoder:
NSObject
.m.
.h 中的代码:
@interface SBQAllArtistsModel : NSObject <NSCoding>
.m 中的代码:
- (void)encodeWithCoder:(NSCoder *)encoder
{
//Encode properties, other class variables, etc
[encoder encodeObject:self.artists forKey:@"artists"];
[encoder encodeObject:self.items forKey:@"items"];
[encoder encodeObject:self.arrays forKey:@"arrays"];
[encoder encodeObject:self.artistFav forKey:@"artistFav"];
}
- (id)initWithCoder:(NSCoder *)decoder
{
self = [super init];
if( self != nil )
{
self.artists = [decoder decodeObjectForKey:@"artists"];
self.items = [decoder decodeObjectForKey:@"items"];
self.arrays = [decoder decodeObjectForKey:@"arrays"];
self.artistFav = [decoder decodeObjectForKey:@"artistFav"];
}
return self;
}
-(NSArray *)favoriteArtists{
NSPredicate *predicate = [NSPredicate predicateWithFormat: @"Favorite == YES"];
return [self.artists filteredArrayUsingPredicate: predicate];
}
最佳答案
我找到了解决方案。
我有两个 NSObject,一个保存我所有的艺术家,每个艺术家一个。因此,在我保存艺术家信息的 NSObject 中,我有一个 BOOL 值,如果我选择该艺术家作为最喜欢的艺术家,我会在其中存储该值。我没有将这个 BOOL 值添加到他的 NSCoding 协议(protocol)方法中,因为 BOOL 不是一个对象,而且我不能,所以我创建了一个 NSNumber 来存储其上的收藏夹的值,添加后NSCoding 协议(protocol)方法,运行良好。
我的艺术家 NSObject 中的代码。
.h
@interface SBQArtistModel : NSObject <NSCoding>
@property (strong, nonatomic) NSString *name;
@property (strong, nonatomic) NSString *bio;
@property (strong, nonatomic) NSString *location;
@property (strong, nonatomic) NSString *linkSoundcloud;
@property (strong, nonatomic) NSString *linkFacebook;
@property (strong, nonatomic) NSString *thumbnail;
@property (strong, nonatomic) NSString *image;
@property (strong, nonatomic) NSNumber *numberFavorite;
@property (nonatomic) BOOL Favorite;
.m
- (void)encodeWithCoder:(NSCoder *)encoder
{
[encoder encodeObject:self.name forKey:@"name"];
[encoder encodeObject:self.bio forKey:@"bio"];
[encoder encodeObject:self.location forKey:@"location"];
[encoder encodeObject:self.linkSoundcloud forKey:@"linkSoundcloud"];
[encoder encodeObject:self.linkFacebook forKey:@"linkFacebook"];
[encoder encodeObject:self.thumbnail forKey:@"thumbnail"];
[encoder encodeObject:self.image forKey:@"image"];
[encoder encodeObject:self.numberFavorite forKey:@"numberFavorite"];
}
- (id)initWithCoder:(NSCoder *)decoder
{
self = [super init];
if( self != nil )
{
self.name = [decoder decodeObjectForKey:@"name"];
self.bio = [decoder decodeObjectForKey:@"bio"];
self.location = [decoder decodeObjectForKey:@"location"];
self.linkSoundcloud = [decoder decodeObjectForKey:@"linkSoundcloud"];
self.linkFacebook = [decoder decodeObjectForKey:@"linkFacebook"];
self.thumbnail = [decoder decodeObjectForKey:@"thumbnail"];
self.image = [decoder decodeObjectForKey:@"image"];
self.numberFavorite = [decoder decodeObjectForKey:@"numberFavorite"];
}
return self;
}
谢谢,我希望已经解释得很好;)
关于ios - NSObject 编码后不会与 NSUserDefaults 一起保存,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22225940/