Ios 使用多个描述符对对象数组进行排序

我正试图整理一堆英雄（物品）。每个英雄都是这样的

@interface Hero : NSObject <NSCoding>

@property (strong,nonatomic) NSString *name;
@property (strong,nonatomic) NSString *correctAnswers;
@property (strong,nonatomic) NSString *falseAnswers;
@property (strong,nonatomic) NSString *bonus;
@property (strong,nonatomic) NSString *level;

-(NSInteger*) inLevel;

+(Hero*) createHero:(NSString*)name
            inLevel:(NSString*)level
          withBonus:(NSString*)bonus
     correctAnswers:(NSString*)correctAnswers
       andFalseOnes:(NSString*)falseAnswers;

- (NSString *)description;

@end

我不知道出了什么问题。有人能指出我的错误吗

-------自解----------- 嘿，谢谢你指出解决方案。这是我给其他有同样问题的人的正确代码

@interface Hero ...
-(NSString*) heroBonus;
-(NSString*) heroLevel;
@end

-(void) sortHeros {
    NSSortDescriptor *level = [NSSortDescriptor sortDescriptorWithKey:@"heroLevel" ascending:NO comparator:^NSComparisonResult(id a, id b) {
        int levelHero1 = [a intValue];
        int levelHero2 = [b intValue];

        ...
    }];

    NSSortDescriptor *bonus = [NSSortDescriptor sortDescriptorWithKey:@"heroBonus" ascending:NO comparator:^NSComparisonResult(id a, id b) {
        int bonusHero1 = [a intValue];
        int bonusHero2 = [b intValue];

        ...
    }];
    ...
}

---

它告诉您，您将密钥路径发送到的类没有实现“bonus”的getter或方法。它还表示“NSCFString，意思是将

奖金

密钥路径发送到字符串对象，而不是

英雄

对象。

您有一个名为“奖金”的NSString*和一个名为“奖金”的NSSortDescriptor*。“可能只是我，但编译器也可能会感到困惑。显示接收崩溃的确切行。我还会将奖金排序描述符的名称更改为sortBonus或其他名称

 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString bonus]: unrecognized selector sent to instance 0x9674520'

@interface Hero ...
-(NSString*) heroBonus;
-(NSString*) heroLevel;
@end

-(void) sortHeros {
    NSSortDescriptor *level = [NSSortDescriptor sortDescriptorWithKey:@"heroLevel" ascending:NO comparator:^NSComparisonResult(id a, id b) {
        int levelHero1 = [a intValue];
        int levelHero2 = [b intValue];

        ...
    }];

    NSSortDescriptor *bonus = [NSSortDescriptor sortDescriptorWithKey:@"heroBonus" ascending:NO comparator:^NSComparisonResult(id a, id b) {
        int bonusHero1 = [a intValue];
        int bonusHero2 = [b intValue];

        ...
    }];
    ...
}