核心数据，用我的 JSON 填充我的 Coredata

Posted 2023-03-13

【中文标题】核心数据，用我的 JSON 填充我的 Coredata

【英文标题】：Core data, populating my Coredata with my jSON

【发布时间】：2012-04-30 15:50:48

【问题描述】：

我的问题在哪里？我想用我的 json 填充我的核心数据，但它只填充最后一个对象，我的意思是这个：

phone.name = [[[json valueForKey:@"boxesDetail"] objectAtIndex:1] valueForKey:@"name"];
        phone.number = [NSNumber numberWithInt:[[[[json valueForKey:@"boxesDetail"] objectAtIndex:1] valueForKey:@"number"] intValue]];

而不是以前的。

这是我的代码：

- (void) add
    NSManagedObjectContext *context = [app managedObjectContext];
    Phone *phone = [NSEntityDescription insertNewObjectForEntityForName:@"Phone" inManagedObjectContext:context];

    if (nameText.text.length <= 0 || numberText.text.length <= 0)
    
        NSLog(@" hey hey, t'as pas oublié kkchose ?");
    
    else
    
        phone.name = nameText.text;
        phone.number = [NSNumber numberWithInt:[ numberText.text intValue]];

        NSLog(@"ADD : %@", phone.name);

        [[NSNotificationCenter defaultCenter] postNotificationName:@"Test" object:self];

        [self dismissModalViewControllerAnimated:YES];
    


    NSString *urlString = [NSString stringWithFormat:@"http://localhost:8888/json.txt"];
    NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:urlString]]; 
    NSError *err;

    NSMutableArray *json = (NSMutableArray* )[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&err];


   for (int i = 0; i != 2; i++)
    
        phone.name = [[[json valueForKey:@"boxesDetail"] objectAtIndex:i] valueForKey:@"name"];
        phone.number = [NSNumber numberWithInt:[[[[json valueForKey:@"boxesDetail"] objectAtIndex:i] valueForKey:@"number"] intValue]];
  


    NSFetchRequest *request = [[NSFetchRequest alloc] init];

    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Phone" inManagedObjectContext:context];

    [request setEntity:entity];

    NSArray *array  = [context executeFetchRequest:request error:&err];

    for (Phone *pho in array)
    
        NSLog(@"NAME %@", pho.name);
        NSLog(@"PHONE %@", pho.number);
    

顺便说一句，如果你想让我不编写循环来填充核心数据，我会感谢你^^

【参考方案1】：

您只在这一行中创建一个托管对象：

NSManagedObjectContext *context = [app managedObjectContext];

然后你在这些行中设置了 3 次 name 和 number 字段：

for (int i = 0; i != 2; i++)

    phone.name = [[[json valueForKey:@"boxesDetail"] objectAtIndex:i] valueForKey:@"name"];
    phone.number = [NSNumber numberWithInt:[[[[json valueForKey:@"boxesDetail"] objectAtIndex:i] valueForKey:@"number"] intValue]];

我猜你想创建和填充三个对象而不是一个。将托管对象的创建移到循环内。

for (int i = 0; i != 2; i++)

    Phone *phone = [NSEntityDescription insertNewObjectForEntityForName:@"Phone" inManagedObjectContext:context];
    phone.name = [[[json valueForKey:@"boxesDetail"] objectAtIndex:i] valueForKey:@"name"];
    phone.number = [NSNumber numberWithInt:[[[[json valueForKey:@"boxesDetail"] objectAtIndex:i] valueForKey:@"number"] intValue]];