核心数据和BOOL设置 [英] Core Data and BOOL setup

问题描述

我正在使用一个应用程序，使用Core Data作为其后端来管理SQLite记录。我有一切使用字符串和数字，但刚刚尝试添加BOOL字段，似乎不能让东西工作。

I am working on an app that uses Core Data as its backend for managing SQLite records. I have everything working with strings and numbers, but have just tried adding BOOL fields and can't seem to get things to work.

在.xcdatamodel，我已经添加一个字段给我的对象叫做 isCurrentlyForSale ，它不是可选的，不是瞬态，而是索引。属性类型设置为布尔值，默认值为NO。

In the .xcdatamodel, I have added a field to my object called isCurrentlyForSale which is not Optional, not Transient, and not Indexed. The attribute's type is set to Boolean with default value NO.

当我从数据模型创建类文件时，为.h头文件中的属性添加的样板代码is：

When I created the class files from the data model, the boilerplate code added for this property in the .h header was:

@property (nonatomic, retain) NSNumber * isCurrentlyForSale;

以及

@dynamic isCurrentlyForSale;

。

我一直使用布尔作为简单的BOOL。我读过，我可以使用NSNumber的 numberWithBool 和 boolValue 方法，但这似乎是一个很多很多额外的代码对于这么简单的东西。

I've always worked with booleans as simple BOOLs. I've read that I could use NSNumber's numberWithBool and boolValue methods, but this seems like an aweful lot of extra code for something so simple.

标题中的@property可以更改为简单的BOOL？

Can the @property in the header be changed to a simple BOOL? If so is there anything to watch out for?

感谢
-John

Thanks -John

推荐答案

简单回复：不，您不能更改 @property 声明以返回 BOOL 。

Simple response: No, you cannot change the @property declaration to return a BOOL.

你可以写一些简单的包装器。我将该属性重命名为 currentlyForSale （这意味着它生成 currentlyForSale 和 setCurrentlyForSale： / code>），然后写两个包装：

You can write some simple wrappers, though. I'd rename the attribute to currentlyForSale (which means it generates currentlyForSale and setCurrentlyForSale:), and then write two wrappers:

- (BOOL) isCurrentlyForSale {
  return [[self currentlyForSale] boolValue];
}

- (void) setIsCurrentlyForSale:(BOOL)forSale {
  [self setCurrentlyForSale:[NSNumber numberWithBool:forSale]];
}

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