滑块练习

import UIKit

class ViewController: UIViewController {

//懒加载创建label

lazy var label:UILabel = {

let l = UILabel(frame:CGRect(x: 20, y: 50, width: 374, height: 50))

l.textAlignment = .center

return l

}()

//懒加载创建slider

lazy var slider:UISlider = {

let s = UISlider(frame:CGRect(x: 20, y: 120, width: 374, height: 30))

return s

}()

//懒加载创建三个slider

lazy var red:UISlider = {

let r = UISlider(frame:CGRect(x: 20, y: 200, width: 374, height: 30))

return r

}()

lazy var green:UISlider = {

let g = UISlider(frame:CGRect(x: 20, y: 250, width: 374, height: 30))

return g

}()

lazy  var blue:UISlider = {

let b = UISlider(frame:CGRect(x: 20, y: 300, width: 374, height: 30))

return b

}()

override func viewDidLoad() {

super.viewDidLoad()

//把label添加到父视图

self.view.backgroundColor = #colorLiteral(red: 0.9098039269, green: 0.4784313738, blue: 0.6431372762, alpha: 1)

self.view.addSubview(label)

label.text = "中华小当家"

//把slider添加到父视图上

self.view.addSubview(slider)

slider.minimumValue = 10.0

slider.maximumValue = 50.0

slider.addTarget(self, action: #selector(changeFontSize), for: .valueChanged)

//控制背景颜色的三个slider

self.view.addSubview(red)

self.view.addSubview(green)

self.view.addSubview(blue)

//设置滑块的颜色

red.thumbTintColor = #colorLiteral(red: 0.9254902005, green: 0.2352941185, blue: 0.1019607857, alpha: 1)

green.thumbTintColor = #colorLiteral(red: 0.4666666687, green: 0.7647058964, blue: 0.2666666806, alpha: 1)

blue.thumbTintColor = #colorLiteral(red: 0.2588235438, green: 0.7568627596, blue: 0.9686274529, alpha: 1)

// 设置滑块的起始值

self.view.backgroundColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)

red.value = 1.0

green.value = 1.0

blue.value = 1.0

//给这三个滑块添加关联事件

red.addTarget(self, action: #selector(changeColor), for: .valueChanged)

green.addTarget(self, action: #selector(changeColor), for: .valueChanged)

blue.addTarget(self, action: #selector(changeColor), for: .valueChanged)

}

func changeFontSize(sender:UISlider){

label.font = UIFont.boldSystemFont(ofSize: CGFloat(sender.value))

}

func changeColor(sender:UISlider){

self.view.backgroundColor = UIColor(red: CGFloat(red.value), green: CGFloat(green.value), blue: CGFloat(blue.value), alpha: 1.0)

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

// Dispose of any resources that can be recreated.

}

}