Swift UIDatePikcer

import UIKit

class ViewController: UIViewController {

    var label:UILabel!
    var datePikcer:UIDatePicker!

    override func viewDidLoad() {
        super.viewDidLoad()

        label = UILabel.init(frame: CGRectMake(10,200,self.view.frame.size.width-20,20))
        label.textAlignment = NSTextAlignment.Center
        label.text = "显示时间"
        self.view.addSubview(label)

        datePikcer = UIDatePicker.init(frame: CGRectMake(10,64,self.view.frame.width-20,100))
        datePikcer.backgroundColor = UIColor.orangeColor()
        datePikcer.datePickerMode = UIDatePickerMode.Date //设置显示的样式
        datePikcer.date = NSDate() //设置默认时间
        datePikcer.addTarget(self,action:Selector("datePickerValueChange:"),forControlEvents: UIControlEvents.ValueChanged)
        self.view.addSubview(datePikcer)

    }

    func datePickerValueChange(sender :UIDatePicker) {

        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd"

        label.text = dateFormatter.stringFromDate(datePikcer.date)
    }
}