NSUserDefaults Save/Read/Clear 儲存/讀取/清除

step1.

// 定義名稱 define key

#define kIsActive        @"isActive"

#define kUserName        @"userName"



step2.

// 讀取資料

-(void)loadInfo {

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    NSLog(@"Name : %@", [defaults stringForKey:kUserName]);

    NSLog(@"isActive : %@", ([defaults boolForKey:kIsActive] ? @"YES" : @"NO"));

}




step3. 

// 儲存資料

-(void)saveInfo {

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    NSString *userName = @"Hank";

    BOOL isActive = YES;

    [defaults setObject:userName forKey:kUserName];

    [defaults setBool:isActive forKey:kIsActive];

}



step4. 

// 清除資料

-(void)clearInfo {

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    

    [defaults removeObjectForKey:kUserName];

    [defaults removeObjectForKey:kIsActive];

}

 



step5.  主程式

// 執行

- (void)viewDidLoad

{

    [super viewDidLoad];

    

    [self saveInfo];

    [self loadInfo];

    

    [self clearInfo];

    [self loadInfo];

}