如何使用Swift在一个UISlider上更改亮度和对比度

import UIKit
import CoreImage

class ViewController: UIViewController {
    @IBOutlet weak var imageView: UIImageView!
    @IBOutlet weak var brightnessSlider: UISlider!
    @IBOutlet weak var contrastSlider: UISlider!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置亮度和对比度的初始值
        brightnessSlider.minimumValue = -1.0
        brightnessSlider.maximumValue = 1.0
        brightnessSlider.value = 0.0
        
        contrastSlider.minimumValue = 0.0
        contrastSlider.maximumValue = 2.0
        contrastSlider.value = 1.0
        
        // 添加值改变事件的监听器
        brightnessSlider.addTarget(self, action: #selector(brightnessChanged), for: .valueChanged)
        contrastSlider.addTarget(self, action: #selector(contrastChanged), for: .valueChanged)
    }
    
    @objc func brightnessChanged() {
        // 获取亮度滑块的当前值
        let brightnessValue = brightnessSlider.value
        
        // 创建一个Core Image滤镜
        let filter = CIFilter(name: "CIColorControls")!
        filter.setValue(CIImage(image: imageView.image!), forKey: kCIInputImageKey)
        
        // 设置亮度值
        filter.setValue(brightnessValue, forKey: kCIInputBrightnessKey)
        
        // 应用滤镜并获取输出图像
        let outputImage = filter.outputImage!
        
        // 将输出图像显示在UIImageView上
        imageView.image = UIImage(ciImage: outputImage)
    }
    
    @objc func contrastChanged() {
        // 获取对比度滑块的当前值
        let contrastValue = contrastSlider.value
        
        // 创建一个Core Image滤镜
        let filter = CIFilter(name: "CIColorControls")!
        filter.setValue(CIImage(image: imageView.image!), forKey: kCIInputImageKey)
        
        // 设置对比度值
        filter.setValue(contrastValue, forKey: kCIInputContrastKey)
        
        // 应用滤镜并获取输出图像
        let outputImage = filter.outputImage!
        
        // 将输出图像显示在UIImageView上
        imageView.image = UIImage(ciImage: outputImage)
    }
}