Question

我已经宣布了一个名为'SharedTranslationsArray'的类，我想在多个视图控制器中使用它。

然后我在视图控制器MainViewController.m中我在“ViewDidLoadMethod”中声明了一个变量的实例，并尝试在单例实例中向对象添加一个对象。没有编译错误/警告，但项目未添加到数组中。

任何建议都将不胜感激。相关代码示例如下感谢

**SharedTranslations.h**
#import "Foundation/Foundation.h"

@interface SharedTranslationsArray : NSObject {
NSMutableArray *translation_set;
}

static SharedTranslationsArray *sharedInstance;
@property (nonatomic, retain) NSMutableArray *translation_set;
+ (SharedTranslationsArray*) sharedInstance;

@end

**SharedTranslations.m** 

#import "SharedTranslationsArray.h"

static SharedTranslationsArray *sharedInstance;
@implementation SharedTranslationsArray
@synthesize translation_set;

\+ (SharedTranslationsArray*)sharedInstance
{   
        if (sharedInstance == nil) {            
            sharedInstance = [[super allocWithZone:NULL] init];


        }
    return sharedInstance;
}

\ + (id)allocWithZone:(NSZone *)zone 
{   
    return [[self sharedInstance]retain];   
}

\ - (id)copyWithZone:(NSZone *)zone
{
    return self;    
}

\ - (id)retain
{   
    return self;    
}

\ - (unsigned)retainCount
{
    return NSUIntegerMax;  //denotes an object that cannot be released
}

\ - (void)release
{
    //do nothing
}

\ - (id)autorelease
{
    return self;    
}

@end

**MainViewController.m**
#import "MainViewController.h"
#import "Translations.h"
#import "SharedTranslationsArray.h"

@implementation MainViewController
\- (void)viewDidLoad {
    NSMutableString *temp = [[NSMutableString alloc] init];

    SharedTranslationsArray *ts = [SharedTranslationsArray sharedInstance];

    Translations *translation = [Translations new];
    translation.shortText = @"short";
    translation.fullText = @"long";
    translation.canDeleted = FALSE;
    translation.active = TRUE;
    [ts.translation_set addObject:translation];
}
@end

Answer 1

确保您实际初始化translation_set！

+ (SharedTranslationsArray*)sharedInstance
{   
        if (sharedInstance == nil) {            
            sharedInstance = [[super allocWithZone:NULL] init];

            sharedInstance.translation_set = [NSMutableArray array];
        }
    return sharedInstance;
}

另外，为什么你把它称为一组但是将它声明为一个数组呢？如果对象的顺序不重要，您可以将其设为NSMutableSet

Objective C - Singleton类实例未初始化

1 个答案: