由于 NSSortDescriptor，SwiftUI NavigationView 跳回前一个视图

如何解决由于 NSSortDescriptor，SwiftUI NavigationView 跳回前一个视图

我有一个带有两个视图的笔记应用：TempNoteView 和 NoteView。

在 NoteView 中按下保存按钮后，它会使用当前日期更新 createdAt。但是，当我返回到我的 TempNoteView 时，使用 saveContext() 保存变量后，导航视图会跳回到上一个视图 (NoteView)。如果我删除 NSSortDescriptor，问题就会消失。我该如何解决这个问题？

TempNoteView

struct TempNoteView: View {
    @Environment(\.managedobjectContext) private var viewContext

    @FetchRequest(
        entity: Note.entity(),sortDescriptors: [
            NSSortDescriptor(keyPath: \Note.createdAt,ascending: false)
        ]
    ) private var notes: FetchedResults<Note>
    
    var isNoteView = false
    
    var body: some View {
            List {
                ForEach(notes,id: \.self) { note in
                    
                    
                    NavigationLink(destination: NoteView(isNoteView: true,note: note)) {
                        Text(note.name ?? "Untitled")
                        Spacer()
                        
                    }
                }.onDelete(perform: deleteNotes)
            }
            .navigationTitle("Notes")
            .navigationBarItems(trailing: Button(action: {addNote()},label: {
                Text("Add Note")
            }))
    }
    
}

NoteView

struct NoteView: View {
        
    // DATABASE ON CORE DATA
    @Environment(\.managedobjectContext) private var viewContext

    @State var noteName: String = ""
    @State var fullText: String = ""
    @State var notePin: Bool = false

    @State var isNoteView = false
    @State var editMode = false
    @State var note : Note
    
    var body: some View {
        if isNoteView == true {
            ZStack {
                NavigationView {
                    vstack {
                        
                        if editMode {
                            ToolBar()
                        }
                            
                        
                    }.padding(.top,60)
                }
                .navigationBarTitle("")
                .navigationBarHidden(true)
                .onAppear(){
                    self.fullText = note.content!
                    self.noteName = note.name!
                    self.notePin = note.pin
                }
                
                vstack {
                    HStack {
                        Spacer()
                        
                        Button(action: {
                            // for saving content
                            if editMode == false {
                                self.editMode = true
                            } else {
                                note.content = fullText
                                note.name = noteName
                                note.createdAt = Date()
                                saveContext()
                                self.editMode = false
                            }
                            
                        }) {
                            if editMode == false {
                                Image("pen").resizable().frame(width:23,height: 23)
                            } else {
                                Image("save").resizable().frame(width:23,height: 23)
                            }
                        }
                        
                   
                    }
                    Spacer()
                }
                

            }
        }
    }
    
    func saveContext() {
        do {
            try viewContext.save()
        } catch {
            let error = error as NSError
            fatalError("Unresolved Error: \(error)")
        }
    }
}

解决方法

尝试保存导航状态并将其传递给每个 NavigationLink：

@State var selectedNote: Note? = nil

var body: some View {
    List {
        ForEach(notes,id: \.self) { note in
            NavigationLink(destination: NoteView(isNoteView: true,note: note),tag: note,selection: $selectedNote,label: {
                Text(note.name ?? "Untitled")
                Spacer()
            })
        }.onDelete(perform: deleteNotes)
    }
    ...