通過AppDelegate將數據保存在自定義類中

Question

我似乎無法將數據保存到我的AppDelegate中的自定義實例對象。我的自定義類很簡單，如下：

Person.h

... 
@interface Person : NSObject { 
    int _age; 
} 

- (void) setAge: (int) age; 
- (int) age; 
@end 

Person.m

#import "Person.h" 

@implementation Person 

- (void) setAge:(int) age { 
    _age = age; 
} 
- (int) age { 
    return _age; 
} 
@end 

然後我在AppDelegate類創建一個Person的實例：

AppDelegate.h

@class Person; 

@interface AccuTaxAppDelegate : NSObject <UIApplicationDelegate> { 
    ... 
Person *person; 
} 
... 
@property (nonatomic, retain) Person *person; 
@end 

AppDelegate.m

... 
#import "Person.h" 

@implementation AccuTaxAppDelegate 

... 
@synthesize person; 

- (void)applicationDidFinishLaunching:(UIApplication *)application { 

    // Override point for customization after app launch  
    [window addSubview:[navigationController view]]; 
    [window makeKeyAndVisible]; 
} 

- (void)applicationWillTerminate:(UIApplication *)application { 
// Save data if appropriate 
} 

#pragma mark - 
#pragma mark Memory management 

- (void)dealloc { 
    [navigationController release]; 
    [window release]; 
    [person release]; 
    [super dealloc]; 
} 
@end 

最後，在我的ViewController代碼我搶的AppDelegate一個句柄，然後搶人的實例，但是當我試圖拯救時代它不似乎工作：

MyViewController

... 
- (void)textFieldDidEndEditing:(UITextField *)textField 
{ 
    NSString *textAge = [textField text]; 
    int age = [textAge intValue]; 
    NSLog(@"Age from text field::%i", age); 

    AppDelegate *appDelegate = 
     (AppDelegate *)[UIApplication sharedApplication].delegate; 

    Person *myPerson = (Person *)[appDelegate person]; 
    NSLog(@"Age before setting: %i", [myPerson age]); 
    [myPerson setAge:age]; 
    NSLog(@"Age after setting: %i", [myPerson age]); 

    [textAge release]; 
} 
... 

上述NSLogs的輸出是：

[Session started at 2010-05-04 18:29:22 +0100.] 
2010-05-04 18:29:28.260 AccuTax[16235:207] Age in text field:25 
2010-05-04 18:29:28.262 AccuTax[16235:207] Age before setting: 0 
2010-05-04 18:29:28.263 AccuTax[16235:207] Age after setting: 0 

爲什麼「時代」不被存儲任何想法？我對Obj-C比較陌生，所以請原諒我，如果我錯過了一些非常簡單的事情！

Answer 1

看起來你從來沒有真正創造者的一個實例 - 在AccuTaxAppDelegate添加包含行

人= [[人頁頭] INIT]的init方法;

否則人無;