swift save and clear user preferences instance

 

Reprinted: http://blog.csdn.net/gishero/article/details/44132245

 

1. import UIKit  
2.   
3. class ViewController: UIViewController {  
4.   
5.     let KEY_NAME = "inputData"  
6.       
7.     @IBOutlet weak var inputText: UITextField!  
8.     @IBOutlet weak var outputText: UITextField!  
9.       
10.     was  out : NSUserDefaults = NSUserDefaults .standardUserDefaults ()  
11.       
12.     override func viewDidLoad() {  
13.         super.viewDidLoad()  
14.         // Do any additional setup after loading the view, typically from a nib.  
15.       
16.         //Get the preference content during initialization and display it in the output  
17.         if var value: AnyObject = ud.objectForKey(KEY_NAME) {  
18.               
19.             //Set if there is a setting item named "inputData"  
20.             outputText.text = value as String  
21.         } else {  
22.               
23.             outputText .text  =  "Item does not exist"  
24.         }  
25.           
26.     }  
27.   
28.     override func didReceiveMemoryWarning() {  
29.         super.didReceiveMemoryWarning()  
30.     }  
31.   
32.     @IBAction func SaveText(sender: AnyObject) {  
33.       
34.         //Set (save) user preferences  
35.         ud.setObject(inputText.text, forKey: KEY_NAME)  
36.       
37.     }  
38.   
39.     @IBAction func ClearText(sender: AnyObject) {  
40.       
41.         //Remove user-set (saved) preferences  
42.         ud.removeObjectForKey(KEY_NAME)  
43.     }  
44. }