在 SwiftUI 中单击 NavigationView 的后退按钮时更新核心数据

Question

User can delete some Core Data in NavigationLink. How to save it when back button clicked and return to NavigationView?

Answer 1

You can do it in the onAppear method of the previous View in the NavigationalStack .

struct ContentView: View {
    @Environment(\.managedObjectContext) var managedObjectContext
    var body: some View {
        Text("")
            .onAppear {
                do {
                    try self.managedObjectContext.save()
                } catch {
                    // handle the Core Data error
                }
        }
    }
}