タイマーを作る

Swift3.0

//
//  ViewController.swift
//  Utility000_3.0
//
//  Created by KimikoWatanabe on 2016/08/22.
//  Copyright © 2016年 FaBo, Inc. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    //時間計測用の変数.
    var cnt : Float = 0

    //時間表示用のラベル.
    var myLabel : UILabel!

    override func viewDidLoad() {

        //ラベルを作る.
        myLabel = UILabel(frame: CGRect(x:0,y:0,width:200,height:50))
        myLabel.backgroundColor = UIColor.orange
        myLabel.layer.masksToBounds = true
        myLabel.layer.cornerRadius = 20.0
        myLabel.text = "Time:\(cnt)"
        myLabel.textColor = UIColor.white
        myLabel.shadowColor = UIColor.gray
        myLabel.textAlignment = NSTextAlignment.center
        myLabel.layer.position = CGPoint(x: self.view.bounds.width/2,y: 200)
        self.view.backgroundColor = UIColor.cyan
        self.view.addSubview(myLabel)

        //タイマーを作る.
        Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(ViewController.onUpdate(timer:)), userInfo: nil, repeats: true)
    }

    //NSTimerIntervalで指定された秒数毎に呼び出されるメソッド.
    func onUpdate(timer : Timer){

        cnt += 0.1

        //桁数を指定して文字列を作る.
        let str = "Time:".appendingFormat("%.1f",cnt)

        myLabel.text = str

    }
}

Swift 2.3

//
//  ViewController.swift
//  Utility000_2.3
//
//  Created by KimikoWatanabe on 2016/08/22.
//  Copyright © 2016年 FaBo, Inc. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    //時間計測用の変数.
    var cnt : Float = 0

    //時間表示用のラベル.
    var myLabel : UILabel!

    override func viewDidLoad() {

        //ラベルを作る.
        myLabel = UILabel(frame: CGRectMake(0,0,200,50))
        myLabel.backgroundColor = UIColor.orangeColor()
        myLabel.layer.masksToBounds = true
        myLabel.layer.cornerRadius = 20.0
        myLabel.text = "Time:\(cnt)"
        myLabel.textColor = UIColor.whiteColor()
        myLabel.shadowColor = UIColor.grayColor()
        myLabel.textAlignment = NSTextAlignment.Center
        myLabel.layer.position = CGPoint(x: self.view.bounds.width/2,y: 200)
        self.view.backgroundColor = UIColor.cyanColor()
        self.view.addSubview(myLabel)

        //タイマーを作る.
        NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: #selector(ViewController.onUpdate(_:)), userInfo: nil, repeats: true)
    }

    //NSTimerIntervalで指定された秒数毎に呼び出されるメソッド.
    func onUpdate(timer : NSTimer){

        cnt += 0.1

        //桁数を指定して文字列を作る.
        let str = "Time:".stringByAppendingFormat("%.1f",cnt)

        myLabel.text = str

    }

}

2.3と3.0の差分

• UIColorの参照方法が変更(UIColor.grayColor()->UIColor.gray)
• CGRect,CGPointの初期化方法の変更(CGRectMake,CGPointMakeの廃止)
• NSTimerの廃止、Timerに変更
• scheduledTimerWithTimeIntervalがscheduledTimer(timeInterval:に変更
• stringByAppendingFormatがappendingFormatに変更

Reference

• Timer Class
  • https://developer.apple.com/reference/foundation/timer