SwiftUI：工作表无法在第一次显示正确的值

Question

我在 SwiftUI 中发现了奇怪的行为。

当我第一次点击列表列时，工作表显示空文本。第二次后似乎正确。

你能帮我吗？

import SwiftUI

let fruits: [String] = [
    "Apple",
    "Banana",
    "Orange",
]

struct ContentView: View {
    @State var isShowintSheet = false
    @State var selected: String = ""
    var body: some View {
        NavigationView {
            List(fruits, id: \.self) { fruit in
                Button(action: {
                    selected = fruit
                    isShowintSheet = true
                }) {
                    Text(fruit)
                }
            }
        }
        .sheet(isPresented: $isShowintSheet, content: {
            Text(selected)
        })
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

列表

第一次点击

第二次点击后

Answer 1

使用.sheet(item:)来代替。这里是固定代码。

已通过 Xcode 12.1 / iOS 14.1 验证

struct ContentView: View {
    @State var selected: String?
    var body: some View {
        NavigationView {
            List(fruits, id: \.self) { fruit in
                Button(action: {
                    selected = fruit
                }) {
                    Text(fruit)
                }
            }
        }
        .sheet(item: $selected, content: { item in
            Text(item)
        })
    }
}

extension String: Identifiable {
    public var id: String { self }
}