NSString *valueToSave = @"someValue";
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:@"preferenceName"];
[[NSUserDefaults standardUserDefaults] synchronize];

然后再拿回来

NSString *savedValue = [[NSUserDefaults standardUserDefaults]
    stringForKey:@"preferenceName"];

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// saving an NSString
[prefs setObject:@"TextToSave" forKey:@"keyToLookupString"];

// saving an NSInteger
[prefs setInteger:42 forKey:@"integerKey"];

// saving a Double
[prefs setDouble:3.1415 forKey:@"doubleKey"];

// saving a Float
[prefs setFloat:1.2345678 forKey:@"floatKey"];

// This is suggested to synch prefs, but is not needed (I didn't put it in my tut)
[prefs synchronize];

检索

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// getting an NSString
NSString *myString = [prefs stringForKey:@"keyToLookupString"];

// getting an NSInteger
NSInteger myInt = [prefs integerForKey:@"integerKey"];

// getting an Float
float myFloat = [prefs floatForKey:@"floatKey"];

下面是如何对Swift做同样的事情;

var valueToSave = "someValue"
NSUserDefaults.standardUserDefaults().setObject(valueToSave, forKey: "preferenceName")

以后把它拿回来;

if let savedValue = NSUserDefaults.standardUserDefaults().stringForKey("preferenceName") {
    // Do something with savedValue
}

在Swift 3.0中

var valueToSave = "someValue"
UserDefaults.standard.set(valueToSave, forKey: "preferenceName")

if let savedValue = UserDefaults.standard.string(forKey: "preferenceName") {

}

就像这样:

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// saving an NSString
[prefs setObject:@"TextToSave" forKey:@"keyToLookupString"];

然后检索:

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// getting an NSString
NSString *myString = [prefs stringForKey:@"keyToLookupString"];

你应该看看苹果的NSUserDefaults类参考，也可以看看这个教程:iPhone编程教程-使用NSUserDefaults保存/检索数据

更准确地说

-(void)saveToUserDefaults:(NSString*)myString
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];

    if (standardUserDefaults) {
        [standardUserDefaults setObject:myString forKey:@"timestamps"];
        [standardUserDefaults synchronize];
    }
}

FirstView

    {
    NSMutableArray *array; }
- (void)viewDidLoad {
    [super viewDidLoad];
    array = [[NSMutableArray alloc]init];
    array = [[NSUserDefaults  standardUserDefaults]objectForKey:@"userlist"];

     NSLog(@"%lu",(unsigned long)array.count);
    if (array>0)
    {
        for (int i=0; i<array.count; i++)
        {
            NSDictionary *dict1 = @{@"Username":[[array valueForKey:@"Username"] objectAtIndex:i],@"Mobilenumber":[[array valueForKey:@"Mobilenumber"] objectAtIndex:i],@"Firstname":[[array valueForKey:@"Firstname"] objectAtIndex:i],@"Lastname":[[array valueForKey:@"Lastname"] objectAtIndex:i],@"dob":[[array valueForKey:@"dob"] objectAtIndex:i],@"image":[[array valueForKey:@"image"] objectAtIndex:i]};
            NSLog(@"%@",dict1);
            NSArray *array1 = [[NSArray alloc]initWithObjects:dict1, nil];
            [[NSUserDefaults standardUserDefaults] setObject:array1 forKey:@"UserList"];
        }

    }
     }

image picker

     - (void)imagePickerController:(UIImagePickerController *)picker         didFinishPickingMediaWithInfo:(NSDictionary *)info {

    UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
    self.imaGe.image = chosenImage;

    [picker dismissViewControllerAnimated:YES completion:NULL];
     }

(IBAction)submitBton:(id)sender { NSMutableArray *array2 = [[NSMutableArray alloc]initWithArray: [[NSUserDefaults standardUserDefaults]objectForKey: @"userlist"]]; UIImage *ima = _imaGe.image; NSData *imagedata = UIImageJPEGRepresentation(ima,100); NSDictionary *dict = @{@"Username":_userTxt.text,@"Lastname":_lastTxt.text,@"Firstname":_firstTxt.text,@"Mobilenumber":_mobTxt.text,@"dob":_dobTxt.text,@"image":imagedata}; [array2 addObject:dict]; [[NSUserDefaults standardUserDefaults]setObject:array2 forKey:@"userlist"]; NSLog(@"%@",array2); [self performSegueWithIdentifier:@"second" sender:self]; } (IBAction)chooseImg:(id)sender { UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker animated:YES completion:NULL]; }

第二视图{ NSMutableArray * arr;｝

- (void)viewDidLoad {
    [super viewDidLoad];

     arr =[[NSMutableArray alloc]init];
    arr = [[NSUserDefaults standardUserDefaults]objectForKey:@"userlist"]; }

#pragma mark- TableView DataSource

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1; }

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return arr.count; }

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *cellId = @"tablecell";
    TableViewCell *cell =[tableView dequeueReusableCellWithIdentifier:cellId];
    cell.userLbl.text =[[arr valueForKey:@"username"] objectAtIndex:indexPath.row];
    cell.ageLbl.text =[[arr valueForKey:@"dob"] objectAtIndex:indexPath.row];
    cell.profileImg.image =[UIImage imageNamed:[[arr valueForKey:@"image"] objectAtIndex:indexPath.row]];
    return cell; }