【发布时间】：2017-12-21 13:44:33
【问题描述】：
所以我设置了一个包含 9 个项目的轮播，每个项目都有不同的渐变。 我希望能够点击一个项目并通过将其变灰或在顶部应用一个带有勾号的视图来显示它已被选中。
问题是，我不确定如何将视图仅应用于已被点击的项目，因为 didSelectItemAt 和 viewForItemAt 函数是分开的。
TLDR：我正在尝试通过在项目顶部应用视图来显示轮播上的项目已被选中。
我的代码：
// Configure slides
var carouselSlides = ["1","2","3","4","5", "6", "7", "8", "9"]
// Set gradient colours
var gradientColours = [
// 0 1
UIColor(red:0.00, green:0.76, blue:1.00, alpha:1.0),
UIColor(red:1.00, green:1.00, blue:0.11, alpha:1.0),
// 2 3
UIColor(red:0.38, green:0.02, blue:0.37, alpha:1.0),
UIColor(red:0.67, green:0.03, blue:0.42, alpha:1.0),
// 4 5
UIColor(red:0.08, green:0.12, blue:0.19, alpha:1.0),
UIColor(red:0.14, green:0.23, blue:0.33, alpha:1.0),
// 6 7
UIColor(red:0.09, green:0.75, blue:0.99, alpha:1.0),
UIColor(red:0.80, green:0.19, blue:0.40, alpha:1.0),
// 8 9
UIColor(red:0.28, green:0.33, blue:0.39, alpha:1.0),
UIColor(red:0.16, green:0.20, blue:0.24, alpha:1.0),
// 10 11
UIColor(red:0.00, green:0.00, blue:0.00, alpha:1.0),
UIColor(red:0.91, green:0.30, blue:0.24, alpha:1.0),
// 12 13
UIColor(red:0.38, green:0.42, blue:0.53, alpha:1.0),
UIColor(red:0.25, green:0.30, blue:0.42, alpha:1.0),
// 14 15
UIColor(red:0.11, green:0.17, blue:0.39, alpha:1.0),
UIColor(red:0.97, green:0.80, blue:0.85, alpha:1.0),
// 16 17
UIColor(red:1.00, green:0.32, blue:0.18, alpha:1.0),
UIColor(red:0.87, green:0.14, blue:0.46, alpha:1.0)]
let indexOfGradientColor = 0
var slideIndex = 0
override var preferredStatusBarStyle: UIStatusBarStyle {
return .lightContent
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
// Carousel configuration
carouselView.type = .coverFlow
carouselView.scrollToItem(at: carouselSlides.count / 2, animated: false)
// Gradient background
let gradient = CAGradientLayer()
gradient.frame = view.bounds
gradient.startPoint = CGPoint(x: 0.0, y: 0.0)
gradient.endPoint = CGPoint(x: 1.0, y: 1.0)
//Set colours
gradient.colors = [
UIColor(red:0.03, green:0.14, blue:0.25, alpha:1.0).cgColor,
UIColor(red:0.02, green:0.04, blue:0.15, alpha:1.0).cgColor]
gradientBackground.layer.addSublayer(gradient)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func carousel(_ carousel: iCarousel, viewForItemAt index: Int, reusing view: UIView?) -> UIView
{
let viewSizeHeight = 160
let viewSizeWidth = 275
let frontView = UIView(frame: CGRect(x: 0, y: 0, width: viewSizeWidth, height: viewSizeHeight))
frontView.contentMode = .center
frontView.layer.cornerRadius = 20;
frontView.layer.masksToBounds = true;
let gradient = CAGradientLayer()
gradient.frame = frontView.bounds
gradient.startPoint = CGPoint(x: 0.0, y: 0.0)
gradient.endPoint = CGPoint(x: 1.0, y: 1.0)
if index == 0 {
//1
gradient.colors = [gradientColours[12].cgColor, gradientColours[13].cgColor]
} else if index == 1 {
//2
gradient.colors = [gradientColours[10].cgColor, gradientColours[11].cgColor]
} else if index == 2 {
//3
gradient.colors = [gradientColours[14].cgColor, gradientColours[15].cgColor]
} else if index == 3 {
//4
gradient.colors = [gradientColours[4].cgColor, gradientColours[5].cgColor]
} else if index == 4 {
//5
gradient.colors = [gradientColours[0].cgColor, gradientColours[1].cgColor]
} else if index == 5 {
//7
gradient.colors = [gradientColours[6].cgColor, gradientColours[7].cgColor]
} else if index == 6 {
//8
gradient.colors = [gradientColours[8].cgColor, gradientColours[9].cgColor]
} else if index == 7 {
//9
gradient.colors = [gradientColours[2].cgColor, gradientColours[3].cgColor]
} else if index == 8 {
//10
gradient.colors = [gradientColours[16].cgColor, gradientColours[17].cgColor]
}
frontView.layer.addSublayer(gradient)
let titleLabel = UILabel(frame: CGRect(x: 8, y: -55, width: viewSizeWidth, height: viewSizeHeight))
titleLabel.font = UIFont.systemFont(ofSize: 32, weight: UIFontWeightHeavy)
titleLabel.textColor = UIColor.white
titleLabel.lineBreakMode = NSLineBreakMode.byWordWrapping
titleLabel.numberOfLines = 4
frontView.addSubview(titleLabel)
titleLabel.text = "\(carouselSlides[index])"
return frontView
}
func numberOfItems(in carousel: iCarousel) -> Int {
return carouselSlides.count
}
func carousel(_ carousel: iCarousel, valueFor option: iCarouselOption, withDefault value: CGFloat) -> CGFloat {
switch (option) {
case .spacing:
return value * 1.05
case .count:
return CGFloat(carouselSlides.count)
default:
return value;
}
}
func carousel(_ carousel: iCarousel, didSelectItemAt index: Int) {
switch index {
case 0:
break
default:
break
}
}
【问题讨论】：