SwiftUI-選擇語言時保存狀態

我已經成功地在 UI 中顯示了語言，但是我遇到了一個問題：當我單擊“保存”按鈕時，它仍然沒有保存我選擇的語言。

我希望當我選擇了語言并單擊 Save Button 時，它會回傳上一頁，當我再次單擊它時，它將顯示我之前選擇的語言。

以上資料僅為模擬，我主要關注它的特點

我目前所有的代碼

struct ContentView: View {
    
    var language: String? = ""
    
    var body: some View {
        NavigationView {
            HStack {
                NavigationLink(destination:LanguageView(language: language)) {
                    Text("Language")
                        .padding()
                    Spacer()
                    Text(language!)
                        .padding()
                }
            }
        }
    }
}


struct LanguageView: View {
    @Environment(\.presentationMode) var pres
    @State var language: String?
    @State var selectedLanguage: String? = ""
    
    var body: some View {

        VStack {
            CustomLanguageView(selectedLanguage: $language)
            
            Button(action: {
                language = selectedLanguage
                pres.wrappedValue.dismiss()
            })
            {
                Text("Save")
                    .foregroundColor(.black)
            }
            .padding()
            Spacer()
        }
    }
}
struct CustomLanguageView: View {
    var language = ["US", "English", "Mexico", "Canada"]
    @Binding var selectedLanguage: String?
    var body: some View {
        LazyVStack {
            ForEach(language, id: \.self) { item in
                SelectionCell(language: item, selectedLanguage: self.$selectedLanguage)
                    .padding(.trailing,40)
                Rectangle().fill(Color.gray)
                    .frame( height: 1,alignment: .bottom)
            }
            .frame(height:15)
        }
    }
}

struct SelectionCell: View {
    let language: String
    @Binding var selectedLanguage: String?
    
    var body: some View {
        HStack {
            Text(language)
            Spacer()
            if language == selectedLanguage {
                Image(systemName: "checkmark")
                    .resizable()
                    .frame(width:20, height: 15)
            }
        }
        .onTapGesture {
            self.selectedLanguage = self.language
        }
    }
}

uj5u.com熱心網友回復：

編輯我之前的答案，因為有些東西阻止了我對我之前的答案的編輯，這個顯示了我用來使它適合我的所有代碼：

import SwiftUI

@main
struct TestApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

struct ContentView: View {
    @State var language: String? = ""
    
    var body: some View {
        NavigationView {
            HStack {
                NavigationLink(destination: LanguageView(language: $language)) {
                    Text("Language").padding()
                    Spacer()
                    Text(language!).padding()
                }
            }
        }
    }
}

struct LanguageView: View {
    @Environment(\.presentationMode) var pres
    @Binding var language: String?
 
    var body: some View {
        VStack {
            CustomLanguageView(selectedLanguage: $language) // <--- here
            Button(action: { pres.wrappedValue.dismiss() }) {  // <--- here
                Text("Save").foregroundColor(.black)
            }.padding()
            Spacer()
        }
    }
}

struct CustomLanguageView: View {
    var language = ["US", "English", "Mexico", "Canada"]
    @Binding var selectedLanguage: String?
    var body: some View {
        LazyVStack {
            ForEach(language, id: \.self) { item in
                SelectionCell(language: item, selectedLanguage: self.$selectedLanguage).padding(.trailing,40)
                Rectangle().fill(Color.gray).frame( height: 1,alignment: .bottom)
            }.frame(height:15)
        }
    }
}

struct SelectionCell: View {
    let language: String
    @Binding var selectedLanguage: String?
    
    var body: some View {
        HStack {
            Text(language)
            Spacer()
            if language == selectedLanguage {
                Image(systemName: "checkmark").resizable().frame(width:20, height: 15)
            }
        }
        .onTapGesture {
            self.selectedLanguage = self.language
        }
    }
}

uj5u.com熱心網友回復：

您可以@State var language在整個程序中使用并使用dismiss，例如這樣，來實作您想要的：

struct LanguageView: View {
    @Environment(\.dismiss) var dismiss  // <--- here
    @Binding var language: String?
 
    var body: some View {
        VStack {
            CustomLanguageView(selectedLanguage: $language) // <--- here
            
            Button(action: {
                dismiss()   // <--- here
            })
            {
                Text("Save").foregroundColor(.black)
            }
            .padding()
            Spacer()
        }
    }
}

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