Ios EasyMapping无法从AFNetworking响应映射int

如果我第一次测试EasyMapping，那么我首先要说的是，这是一个测试项目，在创建新项目时使用Xcode提供的默认核心数据构造函数

当我尝试映射用户的初始登录名时，会出现以下错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for attribute:property = "userID"; desired type = NSNumber; given type = __NSArrayI; value = (
    12345
).'

尝试使用AFNetworking映射POST结果时会导致此错误：

Successfully logged in with responseObject: {
    collection =     {
        items =         (
                        {
                accountid = 12345;
                fname = John;
                lname = Smith;
            }
        );
    };
}

使用以下代码：

// Login server call and resulting Mapping
[[MyHTTPSessionManager sharedManager] POST:@"users" parameters:parameters progress:^(NSProgress * _Nonnull uploadProgress) {

} success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
    NSLog(@"Successfully logged in with responseObject: %@", responseObject);
    NSManagedObjectContext *context = [(AppDelegate*)[[UIApplication sharedApplication] delegate] managedObjectContext];

    // Start EasyMapping
    User *user = [EKManagedObjectMapper objectFromExternalRepresentation:responseObject withMapping:[User objectMapping] inManagedObjectContext:context];
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
}];

User.m objectMapping功能

+ (EKManagedObjectMapping*)objectMapping
{
    return [EKManagedObjectMapping mappingForEntityName:@"User" withRootPath:@"collection.items" withBlock:^(EKManagedObjectMapping * _Nonnull mapping) {
        [mapping mapPropertiesFromDictionary:@{
                                           @"accountid" : @"userID",
                                           @"fname"     : @"firstName",
                                           @"lname"     : @"lastName",
                                           }];
        [mapping setPrimaryKey:@"userID"];
    }];
}

核心数据设置为自动生成以下User+CoreDataProperties.h文件：

#import "User.h"

NS_ASSUME_NONNULL_BEGIN

@interface User (CoreDataProperties)

@property (nullable, nonatomic, retain) NSNumber *userID;
@property (nullable, nonatomic, retain) NSString *firstName;
@property (nullable, nonatomic, retain) NSString *lastName;

@end

NS_ASSUME_NONNULL_END

我不确定我是否遗漏了一些基本的东西。。。我正在使用以下API版本，如我的pod文件中所述：

pod 'AFNetworking', '~> 3.1'
pod 'EasyMapping', '~> 0.18'

---

如果我遗漏了什么，或者您对我如何设置东西有任何疑问，请告诉我。问题似乎与服务器提供的嵌套JSON有关

如果我将行更改为只传递JSON对象

items

所持有的数组，则错误似乎已得到解决

User *user = [EKManagedObjectMapper objectFromExternalRepresentation:[[(NSDictionary*)responseObject objectForKey:@"collection"] objectForKey:@"items"] withMapping:[User objectMapping] inManagedObjectContext:context];

---

问题似乎与服务器提供的嵌套JSON有关

如果我将行更改为只传递JSON对象

items

所持有的数组，则错误似乎已得到解决

User *user = [EKManagedObjectMapper objectFromExternalRepresentation:[[(NSDictionary*)responseObject objectForKey:@"collection"] objectForKey:@"items"] withMapping:[User objectMapping] inManagedObjectContext:context];