如何在iOS应用程序中保存文本数据？

Question

Using my application, the user will take a reading on my application, which will yield a string of text in this format: Reading, Date/Time, Gender, Age . Essentially, what I'm doing is taking this string and storing it in a table view in a different storyboard. Then, every time the application is closed and reopened, the saved values should remain. The action of saving the string should be triggered by pressing a save button. How can this be implemented? Sample code is appreciated.

Answer 1

The easiest solution is to use NSUserDefaults:

   // Add a string & save permanently
   NSMutableArray *savedStrings = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"SavedStrings"]];
   NSString *sampleString = @"Reading, 4 Feb 2017, 12:00, male, 30 years"; 
   [savedStrings addObject:sampleString];
   [[NSUserDefaults standardUserDefaults] setObject:savedStrings forKey:@"SavedString"];
   [[NSUserDefaults standardUserDefaults] synchronize];

    // At launch, get saved strings - use to populate the tableview
    NSMutableArray *savedStrings = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"SavedStrings"]];

Answer 2

I think this will help you...

//In firstViewController.m 
// Create strings to store the text info
NSString *firstName = [self.firstNameTF text];
NSString *lastName  = [self.lastNameTF text];
NSString *age = [self.ageTF text] ;
[defaults synchronize];

// Store the data with key.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

[defaults setObject:firstName forKey:@"firstName"];
[defaults setObject:lastName forKey:@"lastname"];
[defaults setObject:age forKey:@"age"];

//In requiredViewController.m write this code.
// Get the stored data before the view loads
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSString *firstName = [defaults objectForKey:@"firstName"];
NSString *lastName = [defaults objectForKey:@"lastname"];
NSString *ageString = [defaults objectForKey:@"age"];

// Set saved data in UIElements.
self.firstNameLabel.text = firstName;
self.lastNameLabel.text = lastName;
self.ageLabel.text = age;