ios 将字符串保存到 NSUserDefaults？

Save string to the NSUserDefaults?

提问by Shishir.bobby

How to save a string into the NSUserDefaults?

如何将字符串保存到NSUserDefaults?

回答by drawnonward

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

to get it back later

稍后取回

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

回答by Mihir Mehta

more precisely

更确切地说

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

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

回答by Ε Г И ? И О

Here's how to do the same with Swift;

下面是如何用 Swift 做同样的事情；

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

To get it back later;

稍后取回；

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

In Swift 3.0

在 Swift 3.0 中

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

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

}

回答by v01d

Something like this:

像这样的东西：

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

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

Then to retrieve:

然后检索：

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

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

You should really check out Apple's NSUserDefaults Class Reference and also maybe this tutorial: iPhone Programming Tutorial – Saving/Retrieving Data Using NSUserDefaults

您真的应该查看 Apple 的 NSUserDefaults 类参考以及本教程：iPhone 编程教程 – 使用 NSUserDefaults 保存/检索数据

回答by Walter Schurter

Do not forget this statement because otherwise it may not always work:

不要忘记这句话，否则它可能并不总是有效：

[standardUserDefaults synchronize];

回答by Vishnuvardhan Sadu

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];

Retrieving

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"];

回答by Raviprakash

[[NSUserDefaults standardUserDefaults] setValue:aString forKey:aKey]

[[NSUserDefaults standardUserDefaults] setValue:aString forKey:aKey]

回答by Sunkas

A good practice is also to use a constant for the key to avoid bugs where you do not store and read with the same key

一个好的做法是对密钥使用常量，以避免出现不使用相同密钥存储和读取的错误

NSString* const TIME_STAMPS_KEY = @"TIME_STAMPS_KEY";

回答by bharathi kumar

-(void)saveToUserDefaults:(NSString*)string_to_store keys:(NSString *)key_for_the_String
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];

    if (standardUserDefaults) {
        [standardUserDefaults setObject:string_to_store forKey:key_for_the_String];
        [standardUserDefaults synchronize];
    }
}

And call it by:

并通过以下方式调用它：

[self saveToUserDefaults:@"string_to_store" : @"key_for_the_string"];

Retrieve the string by using:

使用以下方法检索字符串：

NSString * stored_string = [[NSUserDefaults standardUserDefaults] stringforkey:key_for_the_String]

回答by Mithun R

FirstView

的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"];
        }

    }
     }

ImagePicker

图像选择器

     - (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];

    }

• (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 {

    的UIImagePickerController *挑选器= [[的UIImagePickerController
    的alloc] INIT]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType =
    UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker 动画:YES 完成:NULL];

    }

---

---

second View{ NSMutableArray *arr; }

第二个视图{ 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; }