保存數據時的NSKeyedArchiver

Question

切換視圖我一直在使用Xcode中的〜9月，現在，我即將完成我的應用程序，但有1個小問題...

背景的一點點。我有一個按鈕，隨機吐出一些數據[在這種情況下的鍛鍊]。在那個窗口中還有一個按鈕來刷新數據並清除標籤。

我想在屏幕上保持randomStretchLabel1，randomStretchLabel2，即使用戶更改視圖或離開應用程序。我希望它保持在屏幕上，只有當用戶點擊randomButton或clearAllWorkouts時才能重新加載。

PIcture of table view to stretchViewController

@interface StretchViewController() 

{ 
    NSArray *stretchOptions; 
} 

- (IBAction)clearAllWorkouts:(id)sender; 

- (IBAction)randomStretchButton1:(id)sender; 
@property (retain, nonatomic) IBOutlet UILabel *randomStretchLabel1; 
@property (retain, nonatomic) IBOutlet UILabel *randomStretchLabel2; 
@end 

@implementation StretchViewController 

@synthesize randomStretchLabel1, randomStretchLabel2; 


    - (IBAction)clearAllWorkouts:(id)sender { 
    randomStretchLabel1.text = @""; 
    randomStretchLabel2.text = @""; 
} 


- (IBAction)randomStretchButton1:(id)sender { 
    stretchOptions = [[NSArray alloc]initWithObjects:@"90/90 Hamstring", @"Adductor", @"Adductor/Groin", @"All Fours Quad Stretch",@"Ankle Circles", @"Ankle On The Knee" @"Anterior Tibialis-SMR", @"Arm Circles", @"Behind Head Chest Stretch", @"Brachialis-SMR", @"Calf Stretch Elbows Against Wall", @"Calf Stretch Hands Against Wall", nil]; 


    int labelIndex = rand()%stretchOptions.count; 
    [randomStretchLabel1 setText:[stretchOptions objectAtIndex:labelIndex]]; 


    int labelIndex2 = rand()%stretchOptions.count; 
    [randomStretchLabel2 setText:[stretchOptions objectAtIndex:labelIndex2]]; 

    } 

改爲下面根據建議，但仍然沒有得到我想要的東西。當我回到表格視圖（所有其他訓練都存儲在其中）時，標籤會自動重置。

- (void)archive 
{ 
    [[NSUserDefaults standardUserDefaults] setValue:randomStretchLabel1.text forKey:@"randomStretchLabel1"]; 
    [[NSUserDefaults standardUserDefaults] setValue:randomStretchLabel2.text forKey:@"randomStretchLabel2"]; 
    [[NSUserDefaults standardUserDefaults] synchronize]; 
} 

- (void)unarchive 
{ 
    randomStretchLabel1.text = [[NSUserDefaults standardUserDefaults] valueForKey:@"randomStretchLabel1"]; 
    randomStretchLabel2.text = [[NSUserDefaults standardUserDefaults] valueForKey:@"randomStretchLabel2"]; 
} 

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
{ 
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 
    if (self) { 
     // Custom initialization 
    } 
    return self; 
} 

- (void)viewDidLoad 
{ 

    [super viewDidLoad]; 
    // Do any additional setup after loading the view. 
} 
    - (void)viewDidUnload 
    { 
     [self setRandomStretchLabel1:nil]; 
     [self setRandomStretchLabel2:nil]; 
     [super viewDidUnload]; 

    } 

- (void)didReceiveMemoryWarning 
{ 
    [super didReceiveMemoryWarning]; 
    // Dispose of any resources that can be recreated. 
} 


- (void)dealloc { 
    [super dealloc]; 
} 
@end 

Answer 1

我希望我能正確理解你的問題。這聽起來像你想要在會話和視圖轉換之間保存標籤的字符串值。要做到這一點，最簡單的方法是使用NSUserDefaults（下面的代碼是一個例子，你可能想要做一些錯誤檢查等）：

- (void)archive 
{ 
    [[NSUserDefaults standardUserDefaults] setValue:label1.text forKey:@"label_1"]; 
    [[NSUserDefaults standardUserDefaults] setValue:label2.text forKey:@"label_2"]; 
    [[NSUserDefaults standardUserDefaults] synchronize]; 
} 

- (void)unarchive 
{ 
    label1.text = [[NSUserDefaults standardUserDefaults] valueForKey:@"label_1"]; 
    label2.text = [[NSUserDefaults standardUserDefaults] valueForKey:@"label_2"]; 
} 

或者你可以使用NSKeyedArchiver/NSKeyedUnarchiver方法，像這樣：

- (void)archive 
{   
    NSString * path1 = @"label1.archive"; 
    if ([NSKeyedArchiver archiveRootObject:label1.text toFile:path1]) { 
     NSLog(@"Archive succeeded"); 
    } else { 
     NSLog(@"Archive failed");    
    } 
} 

- (void)unarchive 
{ 
    NSString * path1 = @"label1.archive"; 
    label1.text = [NSKeyedUnarchiver unarchiveObjectWithFile:path]; 
} 

兩種方法處理所有的基本數據類型的可可，所以你可以用它們爲您舒展等NSArray的

希望這有助於