将Integer设置为非零值时，指定EXC_BAD_ACCESS [英] EXC_BAD_ACCESS when setting Integer to anything else than zero

问题描述

我有这个对象：

@interface Song : NSManagedObject

@property (nonatomic, strong) NSString *songName;
@property (nonatomic) int32_t achievedPoints;

当我设置像这样的属性

Song *song1 = [[SongStore sharedStore] createSong]; 
song1.songName = @"Song 1";
song1.achievedPoints = 0;

一切正常，但是一旦我尝试设置 achiePoints variable = 0我得到一个EXC_BAD_ACCESS。

everything works, however once I try to set the achievedPoints variable to something else than 0 I get an EXC_BAD_ACCESS.

这是 createSong

- (Song *)createSong {
    double order;
    if ([allSongs count] == 0) {
        order = 1.0;
    } else {
        order = [[allSongs lastObject] orderingValue] + 1.0;
    }

    Song *p = [NSEntityDescription insertNewObjectForEntityForName:@"Song" inManagedObjectContext:context];

    [p setOrderingValue:order];
    [allSongs addObject:p];
    return p;
}

我不知道为什么获取该值并将其设置为0，否则会导致程序崩溃。任何帮助是非常感激。

I have no idea why getting the value and setting it to 0 works but anything else than zero crashes the program. Any help is highly appreciated.

推荐答案

这发生在我以前。我不知道确切的哪些设置被搞砸了，但是在你的托管对象模型中有一个设置，控制是否该类应该使用原始值（int，float等）或对象值（NSNumber * ，等）来设置其值。如果这被搞砸了，你认为你正在设置一个原始，当你实际设置一个对象，将发生以下情况：

This has happened to me once before. I don't know exactly which settings gets messed up, but there is a setting in your managed object model, I think, that controls whether or not the class should use primitive values (int, float, etc) or object values (NSNumber *, etc) to set its values. If this gets messed up, and you think you are setting a primitive when you are actually setting an object the following will happen:

//song1.achievedPoints = 0;
song1.achievedPoints = (NSNumber *)0x00000000; 
//This is OK because it is the same as nil

//song1.achievedPoints = 1;
song1.achievedPoints = (NSNumber *)0x00000001; //You can see why this is bad!

我的解决方案是通过创建NSManagedObject子类模板重新生成类，确保已选中使用标量值作为基本元素。

My solution was to regenerate the class via the Create NSManagedObject Subclass template, making sure that Use Scalar Values for Primitives was checked.

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