无法从对象创建 BOOL

Question

我正在关注cocoa programming for mac os x, 4th edition的指南。在第32章我搞砸了代码，我没有备份它，所以我不得不从big nerd ranch下载解决方案。
该项目是关于核心数据关系的，有一个类Employee和一个类Department。

员工.h：

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@class Department;

@interface Employee : NSManagedObject

@property (nonatomic, copy) NSString * firstName;
@property (nonatomic, copy) NSString * lastName;
@property (nonatomic, retain) Department *department;
@property (nonatomic, readonly) NSString *fullName;

@end

员工.m：

#import "Employee.h"
#import "Department.h"


@implementation Employee

@dynamic firstName;
@dynamic lastName;
@dynamic department;

+ (NSSet *)keyPathsForValuesAffectingFullName
{
    return [NSSet setWithObjects:@"firstName", @"lastName", nil];
}

- (NSString *)fullName
{
    NSString *first = [self firstName];
    NSString *last = [self lastName];
    if (!first)
        return last;
    if (!last)
        return first;
    return [NSString stringWithFormat:@"%@ %@", first, last];
}

@end

部门.h：

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>


@interface Department : NSManagedObject

@property (nonatomic, retain) NSString * deptName;
@property (nonatomic, retain) NSSet *employees;
@property (nonatomic, retain) NSManagedObject *manager;
@end

@interface Department (CoreDataGeneratedAccessors)

- (void)addEmployeesObject:(NSManagedObject *)value;
- (void)removeEmployeesObject:(NSManagedObject *)value;
- (void)addEmployees:(NSSet *)values;
- (void)removeEmployees:(NSSet *)values;

@end

部门.m：

#import "Department.h"
#import "Employee.h"

@implementation Department

@dynamic deptName;
@dynamic employees;
@dynamic manager;

- (void)addEmployeesObject:(Employee *)value
{
    NSLog(@"Dept %@ adding employee %@",
          [self deptName], [value fullName]);
    NSSet *s = [NSSet setWithObject:value];
    [self willChangeValueForKey:@"employees"
                withSetMutation:NSKeyValueUnionSetMutation
                   usingObjects:s];
    [[self primitiveValueForKey:@"employees"] addObject:value];
    [self didChangeValueForKey:@"employees"
               withSetMutation:NSKeyValueUnionSetMutation
                  usingObjects:s];
}

- (void)removeEmployeesObject:(Employee *)value
{
    NSLog(@"Dept %@ removing employee %@",
          [self deptName], [value fullName]);
    Employee *manager = (Employee *)[self manager];
    if (manager == value) {
        [self setManager:nil];
    }
    NSSet *s = [NSSet setWithObject:value];
    [self willChangeValueForKey:@"employees"
                withSetMutation:NSKeyValueMinusSetMutation
                   usingObjects:s];
    [[self primitiveValueForKey:@"employees"] removeObject:value];
    [self didChangeValueForKey:@"employees"
               withSetMutation:NSKeyValueMinusSetMutation
                  usingObjects:s];
}


@end

我有那些核心数据关系和实体：

我还使用一些数组控制器将核心数据值绑定到一些出口。
完整的项目可以在“下载解决方案”中找到here.，第 32 章（与我的相同）。 如果您需要更多代码来理解此错误，请告诉我：

2012-10-31 15:27:43.977 Departments[1229:303] Cannot create BOOL from object (
) of class _NSControllerArrayProxy
2012-10-31 15:27:43.989 Departments[1229:303] Cannot create BOOL from object (
) of class _NSControllerArrayProxy

似乎不建议发布整个项目，但如果您说可以，我可以这样做。

PS：我使用的是从解决方案下载的代码，它是一样的但它不起作用，可能是因为我有更高版本的xcode。

Answer 1

看起来像绑定问题。您可能有一个“启用”或“隐藏”绑定（采用 BOOL）与无法转换为 BOOL 的属性相关联。