这是我最后一个问题的后续问题:iOS: Initialise object at start of application for all controllers to use。
我已经按照以下步骤设置了应用程序(忽略数据库前缀):
DBFactoryClass // Built a DataManaging Object for later use in the app
DBDataModel // Is created by the factory, holds all data & access methods
DBViewControllerA // Will show some of the data that DBDataModel holds
moreViewControllers that will need access to the same DBDataModel Object
我将逐步介绍该应用程序,然后最终将发布构建时收到的错误消息。
AppDelegate.h
#import "DBFactoryClass.h"
AppDelegate.m
- (BOOL)...didFinishLaunching...
{
DBFactoryClass *FACTORY = [[DBFactoryClass alloc ]init ];
return YES;
}
DBFactoryClass.h
#import <Foundation/Foundation.h>
#import "DBDataModel.h"
@interface DBFactoryClass : NSObject
@property (strong) DBDataModel *DATAMODEL;
@end
DBFactoryClass.m
#import "DBFactoryClass.h"
@implementation DBFactoryClass
@synthesize DATAMODEL;
-(id)init{
self = [super init];
[self setDATAMODEL:[[DBDataModel alloc]init ]];
return self;
}
@end
ViewControllerA.h
#import <UIKit/UIKit.h>
#import "DBDataModel.h"
@class DBDataModel;
@interface todayViewController : UIViewController
@property (strong)DBDataModel *DATAMODEL;
@property (weak, nonatomic) IBOutlet UILabel *testLabel;
@end
ViewControllerA.m
#import "todayViewController.h"
@implementation todayViewController
@synthesize testLabel;
@synthesize DATAMODEL;
- (void)viewDidLoad
{
todaySpentLabel.text = [[DATAMODEL test]stringValue];
}
@end
DBDataModel.h
#import <Foundation/Foundation.h>
@interface DBDataModel : NSObject
@property (nonatomic, retain) NSNumber* test;
@end
DBDataModel.m
#import "DBDataModel.h"
@implementation DBDataModel
@synthesize test;
-(id)init{
test = [[NSNumber alloc]initWithInt:4];
return self;
}
@end
当我构建它时,出现以下错误:此行中的
EXC_BAD_ACCESS
:@synthesize DATAMODEL;
的
DBFactoryClass.m
最佳答案
@synthesize
的作用是自动生成属性访问器的实现。那里的EXC_BAD_ACCESS
意味着您在执行访问器之一时正在访问垃圾。
这可能发生在这里:
[self setDATAMODEL:[[DBDataModel alloc]init ]];
确保
DBDataModel
的init
实现实际返回合法对象。