////  RootViewController.m#import "RootViewController.h"@interface RootViewController (){    NSMutableArray * dataSource;}@end@implementation RootViewController-(void)createUI{    NSArray * arr = @[@"NSNumber数据:",@"integer:",@"float:",@"double:",@"NSString数据:",@"NSDate数据:",@"NSArray数据:",@"NSDictionary数据:"];    for(int i = 0;i<[arr count];i++)    {        UILabel * label = [[UILabel alloc]initWithFrame:CGRectMake(0, 70 + 40 * i, 140, 30)];        label.text = arr[i];        label.textAlignment = NSTextAlignmentRight;        [self.view addSubview:label];        [label release];    }    for(int i = 1;i<[arr count];i++)    {        UILabel * label = [[UILabel alloc]initWithFrame:CGRectMake(145, 70 + 40 * i, 170, 30)];        label.tag = i;        label.textAlignment = NSTextAlignmentLeft;        label.backgroundColor = [UIColor cyanColor];        [self.view addSubview:label];        [label release];    }}//向userDefaults里面写入数据-(void)writeUserDefaults{    NSUserDefaults * defaults = [NSUserDefaults standardUserDefaults];    NSInteger i = 100;    float f = 50.0f;    double d = 1000.0;    NSString * string = @"字符串";    NSArray * arr = @[@"hello",@"world"];    NSDictionary * dic = @{
   @"name":@"test",@"age":@"19"};    NSDate * date = [NSDate date];    //存入的数据 无论是可变的还是不可变的 读出来以后都是不可变的数据        [defaults setInteger:i forKey:@"int"];    [defaults setFloat:f forKey:@"float"];    [defaults setDouble:d forKey:@"double"];    //基本类型的数据存放在userDefaults以后都会自动转化成NSNumber    [defaults setObject:string forKey:@"string"];    [defaults setObject:arr forKey:@"array"];    [defaults setObject:dic forKey:@"dic"];    [defaults setObject:date forKey:@"date"];    //写入磁盘    [defaults synchronize];}//读数据-(void)readUserDefaults{    NSUserDefaults * defaults = [NSUserDefaults standardUserDefaults];    dataSource = [[NSMutableArray alloc]init];    NSString * intStr = [NSString stringWithFormat:@"%@",[defaults objectForKey:@"int"]];    NSString * floatStr = [NSString stringWithFormat:@"%f",[defaults floatForKey:@"float"]];    NSString * doubleStr = [NSString stringWithFormat:@"%lf",[defaults doubleForKey:@"double"]];    NSString * stringStr = [defaults objectForKey:@"string"];        NSArray * arr = [defaults objectForKey:@"array"];    NSString * arrStr = [arr componentsJoinedByString:@" "];        NSDictionary * dic = [defaults objectForKey:@"dic"];    NSString * dicStr = [NSString stringWithFormat:@"name:%@,age:%@",[dic objectForKey:@"name"],[dic objectForKey:@"age"]];            NSDate * date = [defaults objectForKey:@"date"];    NSDateFormatter * formatter = [[NSDateFormatter alloc]init];    formatter.dateFormat = @"yyyy-MM-dd HH:mm:ss";    NSString * dateStr = [formatter stringFromDate:date];    [formatter release];        [dataSource addObject:intStr];    [dataSource addObject:floatStr];    [dataSource addObject:doubleStr];    [dataSource addObject:stringStr];    [dataSource addObject:dateStr];    [dataSource addObject:arrStr];    [dataSource addObject:dicStr];    }- (void)viewDidLoad{    [super viewDidLoad];    self.navigationItem.title = @"UserDefualts的用法";    self.view.backgroundColor = [UIColor brownColor];    UIBarButtonItem * item = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(pressBarBtn:)];    self.navigationItem.rightBarButtonItem = item;    [item release];    [self createUI];        [self writeUserDefaults];    [self readUserDefaults];}-(void)pressBarBtn:(id)sender{    //查找沙盒目录的路径    NSArray * arr = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString * path = [arr objectAtIndex:0];    NSLog(@"%@",path);        for(int i = 0;i<[dataSource count];i++)    {        UILabel * lable = (UILabel *)[self.view viewWithTag:i + 1];        lable.text = dataSource[i];    }}@end