SwiftUI: popup does not dismiss

问题

In a Swift-UI List (iOS), showing some CoreData Elements, I want to show a popup for each listelement to change an Attribute of the CoreData Element.

In the code below, it is not possible to dismiss the popup.
If I remove the .id(UUID()) from the List, it works fine.

The .id(UUID()) is needed in my app, because I change the predicate "on the fly" and that's the only way I know, to avoid that SwiftUI tries to compare all List-elements of the old and the new result. This performance issue was discussed in Performance Issue with SwiftUI List

Any Ideas how to solve this?

import Foundation
import SwiftUI

struct ContentView: View {
  @FetchRequest(entity: Item.entity(), sortDescriptors: [], predicate: nil) var items: FetchedResults<Item>

  var body: some View {
    VStack
    { Button("Create Testdata"){createTestdata()}
      List(items, id: \.self)
      { item in
        Line(item: item)
      }.id(UUID())
    }
  }
}

struct Line: View {
  @ObservedObject var item : Item
  @State var showSheet = false

  var body: some View {
    Text(item.text!)
    .onLongPressGesture {
      self.showSheet.toggle()// = true
    }
    .popover( isPresented: self.$showSheet,
              arrowEdge: .trailing
            )
    { Pop(showSheet: self.$showSheet, item: self.item )
    }
  }
}

struct Pop: View {
  @Binding var showSheet: Bool
  var item : Item
    //@Environment(\.presentationMode) var presentationMode

    var body: some View {
        VStack {
           Text("CHANGE TO XXXXXXXXX")
            .onTapGesture
            { self.item.text = "XXXXXXX"
              self.showSheet = false
            }
            Text("CHANGE TO YYYYYYYYY")
            .onTapGesture
            { self.item.text = "YYYYYY"
              self.showSheet = false
            }
            Button("Cancel")
            {
                #if os(OSX)
                NSApp.sendAction(#selector(NSPopover.performClose(_:)), to: nil, from: nil)
                #else
                //self.presentationMode.wrappedValue.dismiss() // << behaves the same as below
                self.showSheet = false
                #endif
            }
        }
    }
}

来源：https://stackoverflow.com/questions/60152674/swiftui-popup-does-not-dismiss

标签

ios

swift

performance

popup

swiftui