我正在写NSUserDefaults的使用作为数据存储机制的应用程序,和我打一个问题,试图挽救数据(即符合属性列表协议)时:将NSUserDefaults的不保存的NSDictionary
+ (BOOL)storeAlbum:(Album *)album
{
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *albums = (NSMutableDictionary *)[prefs objectForKey:@"my_adventure_book_albums"];
NSLog(@"Existing albums: %@",albums);
if (!albums)
albums = [NSMutableDictionary dictionaryWithObject:album forKey:@"album"];
else
[albums setObject:album forKey:@"album"];
NSLog(@"%@",album);
[prefs setObject:albums forKey:@"my_adventure_book_albums"];
return [prefs synchronize];
}
我得到这样的输出:
2010-06-29 17:17:09.929 MyAdventureBook[39892:207] Existing albums: (null)
2010-06-29 17:17:09.930 MyAdventureBook[39892:207] test
2010-06-29 17:17:09.931 MyAdventureBook[39892:207] *** -[NSUserDefaults setObject:forKey:]: Attempt to insert non-property value '{
album = test;
}' of class 'NSCFDictionary'.
专辑的说明方法是这样的:
- (NSString *)description
{
// Convert to a NSDictionary for serializing
if (!title) title = @"";
if (!date) date = [NSDate dateWithTimeIntervalSinceNow:0];
if (!coverImage) coverImage = @"";
if (!images) images = [[NSArray alloc] initWithObjects:@"",nil];
//NSDictionary *dict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:title,date,coverImage,images,nil] forKeys:[NSArray arrayWithObjects:@"title",@"date",@"coverImage",@"images",nil]];
//NSDictionary *dict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:title,nil] forKeys:[NSArray arrayWithObjects:@"title",nil]];
//return [dict description];
return @"test";
}
一所有注释掉的行都会有相同的结果,所以我只是决定看看NSString“测试”是否会起作用,它当然不会。
不,结果相同: *** - [NSUserDefaults setObject:forKey:]:尝试插入非属性值'{ album = test;类'NSCFDictionary'的' }'。 – 2010-06-29 21:26:47