带点图像的自定义UIPageControl
带点图像的自定义UIPageControl
提问于 2016-08-10 17:20:08
当我需要定制我的UIPageControl时，我使用了this和this解决方案。
稍微修改一下，以适应新版本的swift：
class myPageControl: UIPageControl {
var activeImage: UIImage!
var inactiveImage: UIImage!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
activeImage = UIImage(named: "active.png")!
inactiveImage = UIImage(named: "inactive.png")!
}
func updateDots()
{
for i in 0 ..< self.subviews.count
{
let dot : UIImageView = imageViewForSubview(self.subviews[i])
if (i == self.currentPage) {
dot.image = activeImage
}
else {
dot.image = inactiveImage
}
}
}
func imageViewForSubview(view: UIView) -> UIImageView {
var dot: UIImageView? = nil
if (view.isKindOfClass(UIView)) {
for subview: UIView in view.subviews {
if (subview is UIImageView) {
dot = (subview as! UIImageView)
}
}
if dot == nil {
dot = UIImageView(frame: CGRectMake(0.0, 0.0, view.frame.size.width, view.frame.size.height))
view.addSubview(dot!)
}
}
else {
dot = (view as! UIImageView)
}
return dot!
}
func setPage(page: Int) {
super.currentPage = page
self.updateDots()
}
}我的问题是，当你第一次启动app时，我不能改变图片。只有当页面改变时，它才会改变。
在viewDidLoad()中，我添加了setPage(0)和updateDots()，但没有结果。我能做错什么呢？
回答 4
Stack Overflow用户
回答已采纳
发布于 2016-12-03 02:18:16
Swift 3.0 ...你知道你是否可以接受声明的风险：“修改现有控件的子视图是脆弱的”。
您必须在viewDidAppear()和页面控件的valueChanged处理程序中调用"updateDots()“。
import UIKit
class CustomImagePageControl: UIPageControl {
let activeImage:UIImage = UIImage(named: "SelectedPage")!
let inactiveImage:UIImage = UIImage(named: "UnselectedPage")!
override func awakeFromNib() {
super.awakeFromNib()
self.pageIndicatorTintColor = UIColor.clear
self.currentPageIndicatorTintColor = UIColor.clear
self.clipsToBounds = false
}
func updateDots() {
var i = 0
for view in self.subviews {
if let imageView = self.imageForSubview(view) {
if i == self.currentPage {
imageView.image = self.activeImage
} else {
imageView.image = self.inactiveImage
}
i = i + 1
} else {
var dotImage = self.inactiveImage
if i == self.currentPage {
dotImage = self.activeImage
}
view.clipsToBounds = false
view.addSubview(UIImageView(image:dotImage))
i = i + 1
}
}
}
fileprivate func imageForSubview(_ view:UIView) -> UIImageView? {
var dot:UIImageView?
if let dotImageView = view as? UIImageView {
dot = dotImageView
} else {
for foundView in view.subviews {
if let imageView = foundView as? UIImageView {
dot = imageView
break
}
}
}
return dot
}
}Stack Overflow用户
发布于 2018-05-28 09:51:41
我稍微改进了@CodenameDuchess的答案。您还可以自定义xibs/故事板上的图像。
class CustomPageControl: UIPageControl {
@IBInspectable var currentPageImage: UIImage?
@IBInspectable var otherPagesImage: UIImage?
override var numberOfPages: Int {
didSet {
updateDots()
}
}
override var currentPage: Int {
didSet {
updateDots()
}
}
override func awakeFromNib() {
super.awakeFromNib()
pageIndicatorTintColor = .clear
currentPageIndicatorTintColor = .clear
clipsToBounds = false
}
private func updateDots() {
for (index, subview) in subviews.enumerated() {
let imageView: UIImageView
if let existingImageview = getImageView(forSubview: subview) {
imageView = existingImageview
} else {
imageView = UIImageView(image: otherPagesImage)
imageView.center = subview.center
subview.addSubview(imageView)
subview.clipsToBounds = false
}
imageView.image = currentPage == index ? currentPageImage : otherPagesImage
}
}
private func getImageView(forSubview view: UIView) -> UIImageView? {
if let imageView = view as? UIImageView {
return imageView
} else {
let view = view.subviews.first { (view) -> Bool in
return view is UIImageView
} as? UIImageView
return view
}
}
}Stack Overflow用户
发布于 2017-02-19 14:12:10
您可以使用UIStackView来达到您想要的效果。
将您的activeImageView和其他inactiveImageView放入aStackView。而不仅仅是在scrollViewDidScroll(_:)中更改activeImageView的索引。
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let index = Int(scrollView.contentOffset.x / scrollView.frame.width)
aStackView.insertArrangedSubview(activeImageView, at: index)
} ps。UIStackView的insertArrangedSubview(_:at:)只更新排列的子视图的堆栈索引，如果它已经在arrangedSubviews列表中的话。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/38869171
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