使用 SwiftUI 关闭视图

Question

我想在用户第一次打开我的应用程序时显示一个说明页面。我已经让它工作了，但我不明白如何返回到 contentView（不重新启动应用程序）。

澄清一下：我希望 InstructionView 上的“关闭此视图”按钮将视图设置为显示为“ContentView”并关闭 InstructionView。现在 viewRouter.setToContentView() 使应用程序崩溃，我无法解决它。

提前致谢

TestDismissApp

import SwiftUI

@main
struct TestDismissApp: App {
    var body: some Scene {
        WindowGroup {

            MotherView()
        }
    }
}

母景

import SwiftUI

struct MotherView : View {
    
    @ObservedObject var viewRouter = ViewRouter()
    
    var body: some View {
        VStack {
            if viewRouter.currentPage == "InstructionView" {
                InstructionView()
            } else if viewRouter.currentPage == "ContentView" {
                ContentView()
            }
        }
    }
}

ViewRouter

import Foundation

class ViewRouter: ObservableObject {
    init() {
        //UserDefaults.standard.set(false, forKey: "didLaunchBefore") remove // if you want to show the instructions again for test reasons
        if !UserDefaults.standard.bool(forKey: "didLaunchBefore") {
            UserDefaults.standard.set(true, forKey: "didLaunchBefore")
            currentPage = "InstructionView"
        } else {
            currentPage = "ContentView"
        }
    }
    
    func setToContentView () {
        currentPage = "ContentView"
    }
    
    @Published var currentPage: String
    
}

内容视图

import SwiftUI

struct ContentView: View {
    var body: some View {
        Text("My wonderful content")
            .padding()
    }
}

InstructionView

import SwiftUI

struct InstructionView: View {
    @Environment(\.dismiss) var dismiss
    @EnvironmentObject var viewRouter: ViewRouter
    var body: some View {
        VStack {
            Text("Instruction: This app shows a wonderful sentence")
            
            Button {
                viewRouter.setToContentView()
                dismiss()
            } label: {
                Text("Dismiss this view")
            }

        }
    }
}

Answer 1

试试这个：

在 MotherView 中使用 @StateObject var viewRouter = ViewRouter() 和 InstructionView().environmentObject(viewRouter)

使用 SwiftUI 关闭视图

Dismissing a view with SwiftUI

view

dismiss

ios

swiftui