Question

我得到JSON的响应存储在一个数组中，我想存储这些值核心数据中的{albumId albumName coverPhotoURL createdDate}请帮助我。

    (
        {
        albumId = 1;
        albumName = UAE;
        coverPhotoURL = "http://1-dot-digiphoto-01.appspot.com/serve?blob-key=AMIfv95XeG-ii4aKZsUB5w-ClP0QUhJZa-o5BQRvdqArCCwg0Ueb13-wAfmyNHgaDdTaFS152_kXkJg5_9386zlfRCDc3fagW7Ekagdd6_VvJl6IscqNkyvVkXKYAqIRe-KqDMpjG-cW";
        createdDate = "10-Jun-2010 06:11 PM";
        description = "photos took in Dubai";
        lastViewedDate = "10-Jun-2010 06:11 PM";
        modifiedDate = "10-Jun-2010 06:11 PM";
        numberOfPhotos = 10;
       }
   )

Answer 1

您需要创建NSManagedObject的子类并定义所有需要的字段

@interface AlbumInfo : NSManagedObject

@property (nonatomic, retain) NSNumber * albumId;
@property (nonatomic, retain) NSString * albumName;
@property (nonatomic, retain) NSString * coverPhotoURL;
@property (nonatomic, retain) NSDate * createdDate;

@end

然后你需要调用这段代码

context = /* Get the NSManagedObject context */

AlbumInfo *item = [NSEntityDescription insertNewObjectForEntityForName:@"AlbumInfo" inManagedObjectContext:context];

item.albumId = @"some value from json";
/* ... so on ...*/

NSError *error = nil;
if (context != nil) {
    if ([managedObjectContext hasChanges] && ![context save:&error]) {
        // Replace this implementation with code to handle the error appropriately.
        // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
    }
}

Answer 2

我假设您创建了一个适合您需要存储的数据的实体。

然后创建NSEntityDescription和NSManagedObject，开始将对象加载到Core Data。

NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"ALbum" inManagedObjectContext:self.managedObjectContext];
NSManagedObject *newAlbum = [[NSManagedObject alloc] initWithEntity:entityDescription insertIntoManagedObjectContext:self.managedObjectContext];

然后您应该将值设置为托管对象

[newPerson setValue:@"photos took in Dubai" forKey:@"description"];

[newPerson setValue:@" UAE" forKey:@"albumName"];

最后一步你应该像这样保存这些改变

NSError *error = nil;

if (![newAlbum.managedObjectContext save:&error]) {

    NSLog(@"Unable to save managed object context.");
    NSLog(@"%@, %@", error, error.localizedDescription);
}

Answer 3

我想建议importing data using MagicalRecord是CoreData的优秀包装器。它提供了数据导入配置方法的约定。

导入功能能够映射数据，即使json模型中的属性与实体相比不同，或者您希望将字符串中表示的日期转换为NSDate

为避免重复输入，MagicalRecord将其作为使用uniqueID的约定。它期望实体Album的uniqueID属性，如albumID，Employee - employeeID等。因此需要按照惯例对其进行建模。根据你的情况，模型就是这样的。

enter image description here

您可以注意到，在albumID的用户信息中，该属性已映射到albumId。同样地，createdDate不是字符串值，而是NSDate。

enter image description here

dateFormat设置为createdDate

的UserInfo

现在配置部分已完成。您可以将日期导入CoreData，如

中所示

NSData *jsonData = //Data from web service;
NSArray *albums = [NSJSONSerialization JSONObjectWithData:jsonData
                                                  options:0
                                                    error:nil];
for (id obj in albums) {
    [Album MR_importFromObject:obj];
}

使用

检查数据是否正确导入

NSArray *savedAlbums = [Album MR_findAll];
Album *album = [savedAlbums lastObject];
NSLog(@"Created Date : %@",album.createdDate);

如何在iOS中的核心数据中存储JSON数据

3 个答案: