如何在 SwiftUI 中更新页面指示器？

Question

接口：SwiftUI
生命周期：SwiftUI
语言：Swift
Xcode版本：12.5

我想在带有核心数据的自定义轮播视图中使用页面指示器。该指标与下面的当前代码一起工作正常，但如果从 Core Data 添加或删除页面，指标的数量不会改变。

添加或删除页面时，pages.count发生了变化，但我检查了func makeUIView()没有再次执行

当 self.pages.count 的值发生变化时，如何自动重新加载 func makeUIView？

struct PageControl : UIViewRepresentable {
    @EnvironmentObject var ani: CarouselModel
    @FetchRequest(entity: Page.entity(),
                  sortDescriptors: [NSSortDescriptor(keyPath: \Page.name, ascending: true)]
    ) var pages: FetchedResults<Page>
    
    func makeUIView(context: Context) -> UIPageControl {
        let view = UIPageControl()
        view.currentPageIndicatorTintColor = UIColor(red: 100/255, green: 255/255, blue: 177/255, alpha: 1.0)
        view.pageIndicatorTintColor = UIColor(red: 100/255, green: 255/255, blue: 177/255, alpha: 1.0).withAlphaComponent(0.2)
        view.numberOfPages = self.pages.count + 1
        
        return view
    }
    
    func updateUIView(_ uiView: UIPageControl, context: Context) {
        // Updating Page Indicator When Ever Page Changes...
        DispatchQueue.main.async {
            uiView.currentPage = Int(self.ani.count)
        }
    }
}

Answer 1

我明白了！

将下面的行从 func makeUIView 放到 func updateUIView

uiView.numberOfPages = pages.count + 1

决赛

func updateUIView(_ uiView: UIPageControl, context: Context) {
            // Updating Page Indicator When Ever Page Changes...
            DispatchQueue.main.async {
                uiView.currentPage = Int(self.ani.count)
                uiView.numberOfPages = pages.count + 1
            }
        }

如何在 SwiftUI 中更新页面指示器？

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