Data binding 父导航视图的SwiftUI更新数据

如何更新位于NavigationView详细信息中的TextField中的数据？我希望在父视图的列表中更新数据。这是我的密码：

class Address: ObservableObject, Identifiable {
    let id = UUID()
    @Published var name: String
    @Published var age: String
    
    init(name: String, age: String) {
        self.name = name
        self.age = age
    }
}
class AddressBook: ObservableObject {
    @Published var addresses: [Address]

    init(addresses: [Address]) {
        self.addresses = addresses
    }
}
struct TestData {
    static let addressbook = AddressBook(addresses: [
        Address(name: "Person1", age: "39"),
        Address(name: "Person2", age: "22")
    ])
}
struct ContentView: View {
    @ObservedObject var addressbook = TestData.addressbook
    
    var body: some View {
        NavigationView {
            List (addressbook.addresses) {address in
                NavigationLink(destination: AddressDetail(address: address)) {
                    Text(address.name)
                }
            }
            .navigationBarTitle("Addressbook")
        }
        
    }
}

struct AddressDetail: View {
    @ObservedObject var address: Address
    
    var body: some View {
        Form {
            TextField("name", text: $address.name)
            
            TextField("age", text: $address.age)
        }
        
    }
}

这段代码不起作用：如果我转到AddressDetail视图，更改TextField值，然后返回，更改不会在列表视图中更新

---

Nico

问题在于

地址

是一个类，因此如果其发布的属性发生了更改，则

地址

中的引用不会更改，而是

内容视图

视图将

地址簿

作为地址容器进行观察

这里是可能的方法的演示（在Xcode 12b/iOS 14上测试并工作，也在11.4/iOS 13.4上）

替代：基于

绑定

（需要更多的更改，因此，对我来说，不太可取，但值得一提

struct Address: Identifiable, Hashable {
    let id = UUID()
    var name: String
    var age: String

    init(name: String, age: String) {
        self.name = name
        self.age = age
    }
}
class AddressBook: ObservableObject {
    @Published var addresses: [Address]

    init(addresses: [Address]) {
        self.addresses = addresses
    }
}
struct TestData {
    static let addressbook = AddressBook(addresses: [
        Address(name: "Person1", age: "39"),
        Address(name: "Person2", age: "22")
    ])
}

struct ContentView: View {
    @ObservedObject var addressbook = TestData.addressbook

    var body: some View {
        NavigationView {
            List (Array(addressbook.addresses.enumerated()), id: \.element) { i, address in
                NavigationLink(destination: AddressDetail(address: self.$addressbook.addresses[i])) {
                    Text(address.name)
                }
            }
            .navigationBarTitle("Addressbook")
        }

    }
}

struct AddressDetail: View {
    @Binding var address: Address

    @State private var name: String
    @State private var age: String

    init(address: Binding<Address>) {
        _address = address
        _name = State(initialValue: _address.wrappedValue.name)
        _age = State(initialValue: _address.wrappedValue.age)
    }
    var body: some View {
        Form {
            TextField("name", text: $name)

            TextField("age", text: $age)
        }
        .onDisappear {
            self.address.name = self.name
            self.address.age = self.age
        }
    }
}

结构地址：可识别、可散列{ 设id=UUID（） 变量名称：String 变量年龄：字符串 init（名称：String，年龄：String）{ self.name=名称 self.age=年龄 } } 类地址簿：ObservieObject{ @已发布的var地址：[地址] 初始化（地址：[地址]）{ self.addresses=地址 } } 结构测试数据{ 静态let addressbook=地址簿（地址：[ 地址（姓名：“Person1”，年龄：“39”）， 地址（姓名：“Person2”，年龄：“22”） ]) } 结构ContentView:View{ @ObservedObject var addressbook=TestData.addressbook var body：一些观点{ 导航视图{ 列表（数组（addressbook.addresses.enumerated（）），id:\.element）{i，中的地址 NavigationLink（目的地：AddressDetail（地址：self.$addressbook.addresses[i]））{ 文本（地址、名称） } } .navigationBarTitle（“地址簿”） } } } 结构AddressDetail:视图{ @绑定变量地址：地址 @国家私有变量名称：String @国家私有变量年龄：字符串 init（地址：Binding）{ _地址 _名称=状态（初始值：_address.wrappedValue.name） _年龄=状态（初始值：_address.wrappedValue.age） } var body：一些观点{ 形式{ TextField（“名称”，text:$name） 文本字段（“年龄”，文本：$age） } 翁迪萨佩尔先生{ self.address.name=self.name self.address.age=self.age } } }

---

谢谢，它很有效！但是这个问题没有其他解决方案吗？在我看来，导航视图中列表后面的编辑表单非常常用。我想将address参数作为$address之类的内容传递，但在闭包中似乎不起作用。您如何使用@environmentObject？@Nico，

@EnvironmentObject

的行为与

@ObservedObject

相同，因此原始问题仍然如第一段所述。另一种方法是使用

@Binding

-请参阅更新的用法。

struct Address: Identifiable, Hashable {
    let id = UUID()
    var name: String
    var age: String

    init(name: String, age: String) {
        self.name = name
        self.age = age
    }
}
class AddressBook: ObservableObject {
    @Published var addresses: [Address]

    init(addresses: [Address]) {
        self.addresses = addresses
    }
}
struct TestData {
    static let addressbook = AddressBook(addresses: [
        Address(name: "Person1", age: "39"),
        Address(name: "Person2", age: "22")
    ])
}

struct ContentView: View {
    @ObservedObject var addressbook = TestData.addressbook

    var body: some View {
        NavigationView {
            List (Array(addressbook.addresses.enumerated()), id: \.element) { i, address in
                NavigationLink(destination: AddressDetail(address: self.$addressbook.addresses[i])) {
                    Text(address.name)
                }
            }
            .navigationBarTitle("Addressbook")
        }

    }
}

struct AddressDetail: View {
    @Binding var address: Address

    @State private var name: String
    @State private var age: String

    init(address: Binding<Address>) {
        _address = address
        _name = State(initialValue: _address.wrappedValue.name)
        _age = State(initialValue: _address.wrappedValue.age)
    }
    var body: some View {
        Form {
            TextField("name", text: $name)

            TextField("age", text: $age)
        }
        .onDisappear {
            self.address.name = self.name
            self.address.age = self.age
        }
    }
}