用swift編寫ios應用-顏色數值查詢

版本：

swift 4，ios 11.2，smulater: iPhone 8
color finder（顏色數值查詢）
顏色主要由紅綠藍三種顏色以及透明度構成，可以根據顏色得到對應的數值

UIColor(red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat)

1.視圖設定

2.滑塊設定

3.添加兩個滑塊

4.添加數字

5.設定數值和背景顏色

6.配對顏色數值

7.配對滑塊

8.編寫代碼

//  ViewController.swift
//  ColorFinder
//
//  Created by lin on 2018/3/23.
//  Copyright © 2018年 lin. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
    var redValue = 255
    var greenValue = 255
    var blueValue = 255

    @IBOutlet weak var redText: UILabel!
    @IBOutlet weak var greenText: UILabel!
    @IBOutlet weak var blueText: UILabel!

    @IBAction func redSliderChanged(_ sender: UISlider) {
        redValue = Int(sender.value)
        redText.text = "R:\(redValue)"
        changBackgroundColor()
    }
    @IBAction func greenSliderChanged(_ sender: UISlider) {
        greenValue = Int(sender.value)
        greenText.text = "G:\(greenValue)"
        changBackgroundColor()
    }
    @IBAction func blueSliderChanged(_ sender: UISlider) {
        blueValue = Int(sender.value)
        blueText.text = "B:\(blueValue)"
        changBackgroundColor()
    }

    func changBackgroundColor(){
        view.backgroundColor = UIColor(red: CGFloat(redValue) / 255, green: CGFloat(greenValue) / 255, blue: CGFloat(blueValue) / 255, alpha: 1)
    }

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

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

9.測試顏色



10.翻轉測試