swift 保存和清空用户首选项实例

 

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

 

import UIKit

class ViewController: UIViewController {

    let KEY_NAME = "inputData"

    @IBOutlet weak var inputText: UITextField!
    @IBOutlet weak var outputText: UITextField!

    var ud: NSUserDefaults = NSUserDefaults.standardUserDefaults()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        //初期化时取得首选项内容，并显示到output中
        if var value: AnyObject = ud.objectForKey(KEY_NAME) {

            //命名为“inputData”的设定项存在的话设定
            outputText.text = value as String
        } else {

            outputText.text = "设定项不存在"
        }

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    @IBAction func SaveText(sender: AnyObject) {

        //设定（保存）用户首选项
        ud.setObject(inputText.text, forKey: KEY_NAME)

    }

    @IBAction func ClearText(sender: AnyObject) {

        //移除用户设定（保存）的首选项
        ud.removeObjectForKey(KEY_NAME)
    }
}