有人可以告诉我如何初始化 NSMutableOrderedSet 吗?
我尝试了以下
NSMutableOrderedSet *answerSet = [NSMutableOrderedSet orderedSet];
但挂在那里日志只是(lldb)
将插入对象答案
#import "Answer.h"
#import "Survey.h"
@implementation Answer
@dynamic count;
@dynamic text;
@dynamic survey;
@end
编辑1:
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
@interface Survey : NSManagedObject
@property (nonatomic, retain) NSDate * dateCreated;
@property (nonatomic, retain) NSString * id;
@property (nonatomic, retain) NSString * note;
@property (nonatomic, retain) NSString * question;
@property (nonatomic, retain) NSMutableOrderedSet *answers;
@end
@interface Survey (CoreDataGeneratedAccessors)
- (void)addAnswersObject:(NSManagedObject *)value;
- (void)removeAnswersObject:(NSManagedObject *)value;
- (void)addAnswers:(NSMutableOrderedSet *)values;
- (void)removeAnswers:(NSMutableOrderedSet *)values;
@end
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
@class Survey;
@interface Answer : NSManagedObject
@property (nonatomic, retain) NSNumber * count;
@property (nonatomic, retain) NSString * text;
@property (nonatomic, retain) Survey *survey;
@end
NSMutableOrderedSet *answerSet = [[NSMutableOrderedSet alloc] initWithCapacity:4];
Answer *ans1 = [NSEntityDescription insertNewObjectForEntityForName:@"Answer"inManagedObjectContext:managedObjectContext];
ans1.text = trimedAns1;
ans1.count = 0;
ans1.survey = survey;
Answer *ans2 = [NSEntityDescription insertNewObjectForEntityForName:@"Answer"inManagedObjectContext:self.managedObjectContext];
ans2.text = trimedAns2;
ans2.count = 0;
ans2.survey = survey;
[answerSet addObject:ans1];
[answerSet addObject:ans2];
[survey setAnswers:answerSet];
NSError *error = nil;
if (![managedObjectContext save:&error]) {
NSLog(@"Can't Save! %@ %@", error, [error userInfo]);
} else {
NSLog(@"Saved question : %@", self.question.text);
}
现在保存到核心数据时出现以下异常:
2013-06-27 22:58:33.955 Simple Survey[718:11903] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for to-many relationship: property = "answers"; desired type = NSSet; given type = __NSOrderedSetM; value = {(
<Answer: 0x8168070> (entity: Answer; id: 0x81c8880 <x-coredata:///Answer/t0F1038D5-DD97-4066-AB7D-E92386A9010B3> ; data: {
count = nil;
survey = "0x81be560 <x-coredata:///Survey/t0F1038D5-DD97-4066-AB7D-E92386A9010B2>";
text = 6;
}),
<Answer: 0x74ec7f0> (entity: Answer; id: 0x74eed40 <x-coredata:///Answer/t0F1038D5-DD97-4066-AB7D-E92386A9010B4> ; data: {
count = nil;
survey = "0x81be560 <x-coredata:///Survey/t0F1038D5-DD97-4066-AB7D-E92386A9010B2>";
text = 7;
})
)}.'