在SwiftUi中学习@EnvironmentObject

Question

我通过示例教程从SwiftUI获得了这段代码，它失败了。代码编译并运行正常，但当点击其中任何一个按钮时，它就会崩溃。我得到的错误是:线程1:致命错误:没有找到ObservableObject类型的UserSettings。作为此视图的祖先，可能缺少用于View.environmentObject(_:)的UserSettings。它附在settings.score += 1线上。

class UserSettings: ObservableObject {
@Published var score = 0}

struct DetailView: View {
@EnvironmentObject var settings: UserSettings
var body: some View {
    Text("Score: \(settings.score)")
}}

struct ContentView: View {
@EnvironmentObject var settings: UserSettings
var body: some View {
    NavigationView {
        VStack {
            Button("Increase Score") {
                settings.score += 1
            }
            NavigationLink(destination: DetailView()) {
                Text("Show Detail View")
            }
        }
    }
}}

Answer 1

EnvironmentObjects必须由anscestor！提供

编辑你的主语到下面的代码：

  @main
struct Your_ App_ Name_Here: App {  // <<: your app name!
    
    var body: some Scene {

        WindowGroup {

            ContentView()
                .environmentObject(UserSettings())

        }
 
    }
 
}