SwiftUI添加PageViewController

創建一個PageVC.swift,遵循協議UIViewControllerRepresentable

UIViewControllerRepresentable要完成兩個必選方法

func makeUIViewController(context: Context) -> UIPageViewController {
}

func updateUIViewController(_ pageVC: UIPageViewController , context: Context) {
}

得到數據

let featuredLandmarks = landmarks.filter{ $0.isFeatured }

將所有的圖片先轉換爲SwiftUIView再轉換爲UIViewController

//    var pages = featuredLandmarks.map {
//        UIHostingController(rootView:
//            Image($0.imageName)
//            .resizable()
//        )
//    }

var pages:[UIViewController]

init() {
//map是將featuredLandmarks所有的數據進行大括號內的操作
    pages = featuredLandmarks.map {
        UIHostingController(rootView:
            Image($0.imageName)
            .resizable()
            .scaledToFill()
        )
    }
}

給pageVC添加dataSource

添加dataSource要遵循協議UIPageViewControllerDataSource,該協議只能在class上遵循,struct不行,所以要寫一箇中間協調源class

同時要遵循協議NSObject，再同時要完成兩個必選方法

class Coordinator: NSObject, UIPageViewControllerDataSource {
    
    //將class外的pages傳進來
    let pages: [UIViewController]
    
    init(pages: [UIViewController]) {
        self.pages = pages
    }
    //往左滑返回的圖片
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        let currentIndex = pages.firstIndex(of: viewController)!
        return currentIndex == 0 ? pages.last : pages[currentIndex - 1]
    }
    //往右滑返回的圖片
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        let currentIndex = pages.firstIndex(of: viewController)!
        return currentIndex == pages.count - 1 ? pages.first : pages[currentIndex + 1]
    }
}

用swiftUI自帶的函數makeCoordinator提供中間協調源

func makeCoordinator() -> Coordinator {
    return Coordinator(pages: pages)
}

添加dataSource

func makeUIViewController(context: Context) -> UIPageViewController {
   let pageVC = UIPageViewController(
        transitionStyle: .scroll,//展示效果
        navigationOrientation: .horizontal//水平效果
    )
    
    //添加dataSource
//        pageVC.dataSource = Coordinator(pages: pages)
    pageVC.dataSource = context.coordinator//表示可以直接從上下文中獲取中間協調源
    
    return pageVC
}

完成updateUIViewController函數

func updateUIViewController(_ pageVC: UIPageViewController , context: Context) {
    pageVC.setViewControllers(
        [pages[0]],//展示的第一個頁面
        direction: .forward,//左劃到下一個頁面
        animated: true
    )
}