Question

我有一个有多种方法的课程。我可以从另一个对象实例化这个类并调用这些方法。当我添加一个新方法时，我不能从类中的另一个方法或其他类中调用它。如果我删除参数然后我可以看到该方法，但当我添加它时，我看不到该方法。我在这里和互联网上搜索过，我已经确定我要导入该类，并且该方法是在.h文件中定义的。我对可能出现的问题感到茫然。

界面：

@interface npcgGetCharacterData : NSObject
@property (strong, nonatomic) NSFetchedResultsController *fetchedResults;
@property (nonatomic, strong) NSManagedObjectContext *managedObjectContext;
@property BOOL debug;
- (NSMutableString *)getRandomRace;
- (NSMutableString *)getRandomAlignment;
- (int)getRandomLevel;
- (NSMutableString *)getRandomNPCType;
- (NSMutableString *)getRandomNPCClass:(NSString *)entityClassType;
@end

实施：

#import "npcgGetCharacterData.h"
#import "RaceEntity+Properties.h"
#import "AlignmentEntity+Properties.h"
#import "NPCTypeEntity+Properties.h"

@implementation npcgGetCharacterData
@synthesize fetchedResults, managedObjectContext, debug;

- (NSMutableString *)getRandomRace {
    NSString *randomRace = [NSString alloc];
    NSArray *resultsArray;
    NSInteger intCount;
    RaceEntity *raceEntity;

    [self setupFetchedResultsController:@"RaceEntity" entityName:@"raceName" entityWhere:@"raceName != 'Any Race'"];
    debug = NO;
    [self performFetch];
    resultsArray = [fetchedResults fetchedObjects];
    intCount = [resultsArray count];
    raceEntity = [resultsArray objectAtIndex:arc4random() % intCount];
    randomRace = raceEntity.raceName;
    self.fetchedResults = nil;
    return randomRace.mutableCopy;
}

- (NSMutableString *)getRandomAlignment {
    NSString *randomAlignment = [NSString alloc];
    NSArray *resultsArray;
    NSInteger intCount;
    AlignmentEntity *alignmentEntity;

    [self setupFetchedResultsController:@"AlignmentEntity" entityName:@"alignmentName" entityWhere:@"alignmentName != 'Any Alignment'"];
    debug = NO;
    [self performFetch];
    resultsArray = [fetchedResults fetchedObjects];
    intCount = [resultsArray count];
    alignmentEntity = [resultsArray objectAtIndex:arc4random() % intCount];
    randomAlignment = alignmentEntity.alignmentName;
    self.fetchedResults = nil;
    return randomAlignment.mutableCopy;
}

- (NSMutableString *)getRandomNPCType {
    NSString *randomNPCType = [NSString alloc];
    NSArray *resultsArray;
    NSInteger intCount;
    NPCTypeEntity *npcTypeEntity;

    [self setupFetchedResultsController:@"NPCTypeEntity" entityName:@"npcTypeName" entityWhere:@"npcTypeName != 'Any Type'"];
    debug = NO;
    [self performFetch];
    resultsArray = [fetchedResults fetchedObjects];
    intCount = [resultsArray count];
    npcTypeEntity = [resultsArray objectAtIndex:arc4random() % intCount];
    randomNPCType = npcTypeEntity.npcTypeName;
    self.fetchedResults = nil;
    return randomNPCType.mutableCopy;
}

- (NSMutableString *)getRandomNPCClass:(NSString *)entityClassType {
    NSString *randomNPCClass = [NSString alloc];

    return randomNPCClass.mutableCopy;
}

- (int)getRandomLevel {
    int intRandomLevel = 0;

    intRandomLevel = (NSInteger)arc4random_uniform(20) + 1;
    return intRandomLevel;
}

- (void)setupFetchedResultsController:(NSString *)entityType entityName:(NSString *)entityName entityWhere:(NSString *)entityWhere{

    NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:entityType];
    if (entityWhere != nil) {
        [request setPredicate:[NSPredicate predicateWithFormat:entityWhere]];
    }
    NSSortDescriptor *entityGroup = [[NSSortDescriptor alloc] initWithKey:entityName ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)];
    NSSortDescriptor *entityNameSort = [[NSSortDescriptor alloc] initWithKey:entityName ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)];
    request.sortDescriptors = [NSArray arrayWithObjects:entityGroup, entityNameSort, nil];

    self.fetchedResults = [[NSFetchedResultsController alloc] 
          initWithFetchRequest:request
          managedObjectContext:self.managedObjectContext
          sectionNameKeyPath:nil
          cacheName:nil];
}

- (void)performFetch {
    if (self.fetchedResults) {
        if (self.fetchedResults.fetchRequest.predicate) {
            if (self.debug) NSLog(@"[%@ %@] fetching %@ with predicate: %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd), self.fetchedResults.fetchRequest.entityName, self.fetchedResults.fetchRequest.predicate);
        } else {
            if (self.debug) NSLog(@"[%@ %@] fetching all %@ (i.e., no predicate)", NSStringFromClass([self class]), NSStringFromSelector(_cmd), self.fetchedResults.fetchRequest.entityName);
        }
        NSError *error;
        [self.fetchedResults performFetch:&error];
        if (error) NSLog(@"[%@ %@] %@ (%@)", NSStringFromClass([self class]), NSStringFromSelector(_cmd), [error localizedDescription], [error localizedFailureReason]);
        if (self.debug) {
            NSLog(@"Number of Objects = %i", [[self.fetchedResults fetchedObjects] count]);
        }
    } else {
        if (self.debug) NSLog(@"[%@ %@] no NSFetchedResultsController (yet?)", NSStringFromClass([self class]), NSStringFromSelector(_cmd));
    }

}

@end

调用方法。这是来自不同的对象：

- (IBAction)GenerateNPCClick:(id)sender {
    npcgGenerateAttribute *nga = [npcgGenerateAttribute alloc];
    npcgGetCharacterData *ngc = [npcgGetCharacterData alloc];
    ngc.managedObjectContext = self.managedObjectContext;
    int intValue = 0;
    NSMutableString *textViewHolder = [NSMutableString alloc];
    for (NSInteger i = 0; i < 6; i++) {
        intValue = nga.generate4D6;
        if (i == 0) {
            textViewHolder = [NSMutableString stringWithFormat:@"%d", intValue];
        } else {
            [textViewHolder appendString:@"\n"];
            [textViewHolder appendString:[NSMutableString stringWithFormat:@"%d", intValue]];
        }
    }
    NSMutableString *strRace = ngc.getRandomRace;
    [textViewHolder appendString:@"\n"];
    [textViewHolder appendString:@"Race: "];
    [textViewHolder appendString:strRace];
    NSMutableString *strAlignment = ngc.getRandomAlignment;
    [textViewHolder appendString:@"\n"];
    [textViewHolder appendString:@"Alignment: "];
    [textViewHolder appendString:strAlignment];
    int intLevel = ngc.getRandomLevel;
    [textViewHolder appendString:@"\n"];
    [textViewHolder appendString:@"Level: "];
    [textViewHolder appendString:[NSMutableString stringWithFormat:@"%d", intLevel]];
    NSMutableString *strNPCType = ngc.getRandomNPCType;
    [textViewHolder appendString:@"\n"];
    [textViewHolder appendString:@"NPC Type: "];
    [textViewHolder appendString:strNPCType];
    [ngc getRandomNPCClass:@"TestString"];
    self.textViewMessageSpace.text = textViewHolder;
}

给我带来麻烦的方法是getRandomNPCClass方法。所有其他getRandom方法都在工作。

忘记包含错误消息：属性'getRandomNPCClass'不在'npcgGetCharacterData *'类型的对象上。当我尝试从另一个对象调用它时，我得到了这个。

感谢您的帮助。

Answer 1

问题是如何创建对象：

npcgGetCharacterData *ngc = [npcgGetCharacterData alloc];

您正在混淆初始化消息，因此这就是您在尝试将其用作正确初始化对象时遇到麻烦的原因。由于您尚未定义init方法，因此将使用NSObject的init方法初始化对象：

npcgGetCharacterData *ngc = [[npcgGetCharacterData alloc]init];

此外，我希望记住关于访问者的Objective-C约定与Java和C ++不同。你不要调用getter getRandomNPCClass，而是调用randomNPCClass。

Objective-C为什么我的类方法对类中的其他方法或其他对象不可见？

1 个答案: