核心数据可转换属性（NSArray）为空

Question

将NSArray保存到可转换的Core Data属性时，该对象将无法在后续获取其实体时进行访问。但是，之后的任何提取都可以使用它。这是怎么回事？

我可以在我的ios应用程序中的一个位置设置和保存Core Data实体及其属性。然后我去阅读最近保存的实体。除可转换的NSArrays之外的所有属性都可用。由于某种原因，数组显示为空（当在日志中打印它看起来像这样：route = "( )"。如果应用程序关闭然后再次打开，该属性不再为空。任何想法？

我知道将NSArray保存为可转换属性并不是最佳做法。你能解释一下为什么会这样吗？

更新1

NSArray充满了CLLocation对象。

控制台中没有打印错误或警告。他们的任何编译器警告或错误也不是。

更新2

下面是我为此问题撰写的XCTest。直到最后一次断言（如预期的那样），测试才会失败。

- (void)testRouteNotNil {
    // This is an example of a performance test case.
    NSMutableArray *route;
    for (int i = 0; i < 500; i++) {
        CLLocation *location = [[CLLocation alloc] initWithLatitude:18 longitude:18];
        [route addObject:location];
    }
    NSArray *immutableRoute = route;

    // Save the workout entity
    //   Just use placeholder values for the XCTest
    //   The method below works fine, as the saved object exists when it is fetched and no error is returned.
    NSError *error = [self saveNewRunWithDate:@"DATE01" time:@"TIME" totalSeconds:100 distance:[NSNumber numberWithInt:100] distanceString:@"DISTANCE" calories:@"CALORIES" averageSpeed:[NSNumber numberWithInt:100] speedUnit:@"MPH" image:[UIImage imageNamed:@"Image"] splits:route andRoute:immutableRoute];
    XCTAssertNil(error);

    // Fetch the most recently saved workout entity
    RunDataModel *workout = [[[SSCoreDataManager sharedManager] fetchEntityWithName:@"Run" withSortAttribute:@"dateObject" ascending:NO] objectAtIndex:0];
    XCTAssertNotNil(workout);

    // Verify that the fetched workout is the one we just saved above
    XCTAssertEqual(workout.date, @"DATE01");

    // Check that the any non-NSArray object stored in the entity is not nil
    XCTAssertNotNil(workout.distance);

    // Check that the route object is not nil
    XCTAssertNotNil(workout.route);
}

更新3

如下所示，这是在Xcode中设置Core Data模型的方式。选择了route属性。请注意，无论有没有transient属性，我都尝试过它。我需要添加Value Transformer Name，那是什么？

更新4

核心数据管理代码本身来自我的GitHub repo，SSCoreDataManger（根据我的知识很有效）。

这是saveNewRunWithDate方法：

- (NSError *)saveNewRunWithDate:(NSString *)date time:(NSString *)time totalSeconds:(NSInteger)totalSeconds distance:(NSNumber *)distance distanceString:(NSString *)distanceLabel calories:(NSString *)calories averageSpeed:(NSNumber *)speed speedUnit:(NSString *)speedUnit image:(UIImage *)image splits:(NSArray *)splits andRoute:(NSArray *)route {
    RunDataModel *newRun = [[SSCoreDataManager sharedManager] insertObjectForEntityWithName:@"Run"];
    newRun.date = date;
    newRun.dateObject = [NSDate date];
    newRun.time = time;
    newRun.totalSeconds = totalSeconds;
    newRun.distanceLabel = distanceLabel;
    newRun.distance = distance;
    newRun.calories = calories;
    newRun.averageSpeed = speed;
    newRun.speedUnit = speedUnit;
    newRun.image = image;
    newRun.splits = splits; // This is also an issue
    newRun.route = route; // This is an issue
    return [[SSCoreDataManager sharedManager] saveObjectContext];
}

以下是RunDataModel NSManagedObject接口：

/// CoreData model for run storage with CoreData
@interface RunDataModel : NSManagedObject

@property (nonatomic, assign) NSInteger totalSeconds;
//  ... 
// Omitted most attribute properties because they are irrelevant to the question
//  ...
@property (nonatomic, strong) UIImage *image;

/// An array of CLLocation data points in order from start to end
@property (nonatomic, strong) NSArray *route;

/// An array of split markers from the run
@property (nonatomic, strong) NSArray *splits;

@end

在实现中，使用@dynamic设置这些属性

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