ios - iOS 中的数字格式问题

Question

在我的 iOS 应用程序中，我尝试在应用程序第一次执行时填充核心数据存储。我在我的 AppDelegate.m 文件中使用了以下代码，我将作为示例展示我如何创建实体的一个对象:

     //creating new managedObject

     NSManagedObject *favoriteThing = [NSEntityDescription insertNewObjectForEntityForName:@"FavoriteThing" inManagedObjectContext:[self managedObjectContext]];


    //extracting year,month and day from current date

    todayDate = [NSDate date];        
    NSCalendar* calendar = [NSCalendar currentCalendar];
    NSDateComponents* components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit fromDate:todayDate]; // Get necessary date components

    //converting components      
    NSNumber *yearBuscado = [NSNumber numberWithLong:[components year]];
    NSNumber *mesBuscado = [NSNumber numberWithLong:[components month]];
    NSNumber *diaBuscado = [NSNumber numberWithLong:[components day]];

    //populating managedObject

    [favoriteThing setValue:@"If done, swipe to right " forKey:@"thingName"];//String
    [favoriteThing setValue:[NSNumber numberWithInt:10] forKey:@"displayOrder"];//Integer32   
    [favoriteThing setValue:[NSNumber numberWithInt:yearBuscado] forKey:@"todoYear"];//Integer32
    [favoriteThing setValue:[NSNumber numberWithInt:mesBuscado] forKey:@"todoMonth"];//Integer32
    [favoriteThing setValue:[NSNumber numberWithInt:diaBuscado] forKey:@"todoDay"];//Integer32
    [favoriteThing setValue:@"Urgent" forKey:@"urgent"];//String
    [favoriteThing setValue:@"Yellow" forKey:@"color"];//String
    [favoriteThing setValue:@"Not deleted" forKey:@"isSemiDeleted"];//String
    [favoriteThing setValue:@"Not done" forKey:@"isDone"];//String

这是第一次启动应用程序后存储的内容(从 SQLite 管理器中提取):

我需要的是存储今天(2014-01-04)的预期值:

todoYear = 2014
todoMonth = 1
todoDay = 4

这三个属性来自类型Integer 32我究竟做错了什么？感谢您的宝贵时间。

Answer 1

您错误地使用 NSNumber 对象调用 numberWithInt，而是直接使用该 NSNumber 调用 setValue

todayDate = [NSDate date];        
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDateComponents* components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit fromDate:todayDate]; // Get necessary date components

//converting components      
NSNumber *yearBuscado = [NSNumber numberWithInteger:[components year]];
NSNumber *mesBuscado = [NSNumber numberWithInteger:[components month]];
NSNumber *diaBuscado = [NSNumber numberWithInteger:[components day]];

[favoriteThing setValue:yearBuscado forKey:@"todoYear"];//Integer32
[favoriteThing setValue:mesBuscado forKey:@"todoMonth"];//Integer32
[favoriteThing setValue:diaBuscado forKey:@"todoDay"];//Integer32

此外，您还可以从 CoreData 模型生成模型类。这样您就可以通过 Properties 为 NSManagedObject 设置值，而不是进行键值编码。

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FavoriteThing *favoriteThing = [NSEntityDescription insertNewObjectForEntityForName:@"FavoriteThing" inManagedObjectContext:[self managedObjectContext]];
[favoriteThing setBuscado: yearBuscado];