获取CoreData时，如何在swiftUI中显示活动指示器？

当我在swiftUI中创建或更新CoreData条目时，我的应用程序需要一段时间才能更新。在此期间，我想以活动指示器的形式提供一些视觉反馈。接下来，我可以让加载视图出现，但如何让它在获取更新条目后消失

内容视图

加载视图

---

不确定你是否找到了这个问题的答案。。。在您的代码中，正在使用常量值true调用ActivityIndicatorSaniMating:

如果将其更改为使用LoadingView.isShowing，则当绑定（也设置为true的常量值）从true更改为false时，活动指示器将被隐藏

例：

import SwiftUI
import CoreData

struct ContentView: View {

    @FetchRequest(entity: DiaryItem.entity(), sortDescriptors: [
        NSSortDescriptor(keyPath: \DiaryItem.createdAt, ascending: false),
    ]) var diaryItems : FetchedResults<DiaryItem>

    var body: some View {
        LoadingView(isShowing: .constant(true)) {
            HStack {
                ForEach(self.diaryItems) { diaryItem in
                    DiaryItemView(
                        title: diaryItem.title!,
                        createdAt: "\(diaryItem.createdAt!)",
                        diaryItem: diaryItem
                    )
                }
            }
        }
    }
}

struct ActivityIndicator: UIViewRepresentable {

    @Binding var isAnimating: Bool
    let style: UIActivityIndicatorView.Style

    func makeUIView(context: UIViewRepresentableContext<ActivityIndicator>) -> UIActivityIndicatorView {
        return UIActivityIndicatorView(style: style)
    }

    func updateUIView(_ uiView: UIActivityIndicatorView, context: UIViewRepresentableContext<ActivityIndicator>) {
        isAnimating ? uiView.startAnimating() : uiView.stopAnimating()
    }
}

struct LoadingView<Content>: View where Content: View {

    @Binding var isShowing: Bool
    var content: () -> Content

    var body: some View {
        GeometryReader { geometry in
            ZStack(alignment: .center) {

                self.content()
                    .disabled(self.isShowing)
                    .blur(radius: self.isShowing ? 3 : 0)

                VStack {
                    ActivityIndicator(isAnimating: .constant(true), style: .large)
                }
                .frame(width: geometry.size.width / 2,
                       height: geometry.size.height / 5)
                .background(Color.secondary.colorInvert())
                .foregroundColor(Color.primary)
                .cornerRadius(20)
                .opacity(self.isShowing ? 1 : 0)
            }
        }
    }
}

struct ContentView: View {
    @State var isLoading = true //Added to track when loading is happening

    @FetchRequest(entity: DiaryItem.entity(), sortDescriptors: [
        NSSortDescriptor(keyPath: \DiaryItem.createdAt, ascending: false),
    ]) var diaryItems : FetchedResults<DiaryItem>

    var body: some View {
        LoadingView(isShowing: $isLoading) {
            ...
        }
    }
}

ActivityIndicator(isAnimating: $isShowing, style: .large)