【发布时间】：2018-11-06 13:04:39
【问题描述】：
我正在开发一个使用 alamofire 和 swiftyJSON 与 API 交互的 iOS 应用程序。在这个 api 中，我得到了一堆返回的值，其中一个是图像。返回的图像以数组的形式出现，但我能够遍历数组并显示单个图像。为了使应用程序更高级，我决定在我的应用程序中实现 UIPageViewController 类。我调用了 API 函数并尝试将我的图像传递给视图控制器。
我的故事板中的事物列表
- 一个 UIPageView
- 一个嵌入了 UIImage 的 UiViewController。
据我所知，我的代码很好，但是当我运行应用程序时，控制台中没有任何反应。以下是我的代码。
protocol ProductImagesPageViewControllerDelegate: class {
func setupPageController(numberOfPages: Int)
func turnPageController(to index: Int)
}
class ProductPageVC: UIPageViewController {
weak var pageViewControllerDelegate: ProductImagesPageViewControllerDelegate?
override func viewDidLoad() {
super.viewDidLoad()
automaticallyAdjustsScrollViewInsets = false
dataSource = self
delegate = self
}
func configureImg() {
let productId = ProductServices.instance.selectedProduct?.id
ProductServices.instance.findIndividualProducts(id: productId!, completion: { (success) in
if success {
ProductServices.instance.productDetails.forEach({ (productDetail) in
let images = productDetail.productImg.count
if images > 0 {
for image in 0..<(images) {
let imageVC = self.storyboard?.instantiateViewController(withIdentifier: PRODUCT_IMAGE_VC)
self.controllers.append(imageVC!)
}
}
})
}
})
}
lazy var controllers: [UIViewController] = {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
var controllers = [UIViewController]()
let productId = ProductServices.instance.selectedProduct?.id
ProductServices.instance.findIndividualProducts(id: productId!, completion: { (success) in
if success {
ProductServices.instance.productDetails.forEach({ (productDetail) in
let images = productDetail.productImg.count
if images > 0 {
for image in 0..<(images) {
let imageVC = storyboard.instantiateViewController(withIdentifier: PRODUCT_IMAGE_VC)
controllers.append(imageVC)
}
}
})
}
})
self.pageViewControllerDelegate?.setupPageController(numberOfPages: controllers.count)
return controllers
}()
func turnToPage(index: Int)
{
let controller = controllers[index]
var direction = UIPageViewControllerNavigationDirection.forward
if let currentVC = viewControllers?.first {
let currentIndex = controllers.index(of: currentVC)!
if currentIndex > index {
direction = .reverse
}
}
self.configureDisplaying(viewController: controller)
setViewControllers([controller], direction: direction, animated: true, completion: nil)
}
func configureDisplaying(viewController: UIViewController)
{
for (index, vc) in controllers.enumerated() {
if viewController === vc {
if let imageVC = viewController as? ImagesVC {
imageVC.configureImage(productIndex: index)
self.pageViewControllerDelegate?.turnPageController(to: index)
}
}
}
}
}
// MARK: - UIPageViewControllerDataSource
extension ProductPageVC : UIPageViewControllerDataSource
{
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController?
{
if let index = controllers.index(of: viewController) {
if index > 0 {
return controllers[index-1]
}
}
return controllers.last
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
if let index = controllers.index(of: viewController) {
if index < controllers.count - 1 {
return controllers[index + 1]
}
}
return controllers.first
}
}
extension ProductPageVC : UIPageViewControllerDelegate {
func pageViewController(_ pageViewController: UIPageViewController, willTransitionTo pendingViewControllers: [UIViewController])
{
self.configureDisplaying(viewController: pendingViewControllers.first as! ImagesVC)
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool)
{
if !completed {
self.configureDisplaying(viewController: previousViewControllers.first as! ImagesVC)
}
}
}
这是我的 ImageVC 代码
class ImagesVC: UIViewController {
@IBOutlet weak var imageView: UIImageView!
func configureImage(productIndex : Int) -> Void {
ProductServices.instance.productDetails.forEach { (productImg) in
if productImg.productImg.count > 0 {
imageView.sd_setImage(with: URL(string: productImg.productImg[productIndex]!) )
} else {
imageView.image = UIImage(named: "image_not_found")
}
}
}}
这是我的 HeaderImageView 代码
class HeaderImageVC: UIView {
@IBOutlet weak var pageControl: UIPageControl!
}
extension HeaderImageVC : ProductImagesPageViewControllerDelegate {
func setupPageController(numberOfPages: Int)
{
pageControl.numberOfPages = numberOfPages
}
func turnPageController(to index: Int)
{
pageControl.currentPage = index
}
}
我不知道为什么代码不起作用，但会根据要求提供更多代码。谢谢。
根据建议
var images = (ProductServices.instance.productDetails.first?.productImg)
lazy var controllers: [UIViewController] = {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
var controllers = [UIViewController]()
if let images = self.images {
for image in images {
let imageVC = storyboard.instantiateViewController(withIdentifier: PRODUCT_IMAGE_VC)
controllers.append(imageVC)
}
}
self.pageViewControllerDelegate?.setupPageController(numberOfPages: controllers.count)
return controllers
}()
这仍然返回空
【问题讨论】：
-
你在主线程上设置图像吗？
-
我不知道在主线程上设置是否有问题，但我没有指定线程
-
打印当前线程或放置断点以检查您正在设置图像的线程。或者，您可以指定线程以排除线程问题。
-
它没有在主线程上运行
-
请在主线程上设置图像。 DispatchQueue.main.async { // 设置图片 }
标签： ios json swift alamofire sdwebimage