Go to a new view using SwiftUI

问题:

I've got a basic view with a button using SwiftUI and I'm trying to present a new screen/view when the button is tapped. How do I do this? Am I suppose to create a delegate for this view that will tell the app's SceneDelegate to present a new view controller?

import SwiftUI

struct ContentView : View {
    var body: some View {
        VStack {
            Text("Hello World")
            Button(action: {
                //go to another view
            }) {
                Text("Do Something")
                    .font(.largeTitle)
                    .fontWeight(.ultraLight)
            }
        }
    }
}

回答1:

The key is to use a NavigationView and a NavigationLink:

import SwiftUI

struct ContentView : View {
    var body: some View {
        NavigationView {
            VStack {
                Text("Hello World")
                NavigationLink(destination: DetailView()) {
                    Text("Do Something")
                }
            }
        }
    }
}

回答2:

Here's another way to present a view WITHOUT using NavigationView. This is like UIKit's UIModalPresentationStyle.currentContext.

struct PresenterButtonView: View {
var body: some View {
    PresentationButton(Text("Tap to present"),
                       destination: Text("Hello world"))
}}

回答3:

I made a ViewModifier for this. It also means that there is no navigation bar. You can call it like so:

.navigate(to: MainPageView(), when: $willMoveToNextScreen)

This can be attached to anything, so I typically attach it to the end of the body, for example:

@State private var willMoveToNextScreen = false

var body: some View {
    VStack {
        /* ... */
    }
    .navigate(to: MainPageView(), when: $willMoveToNextScreen)
}

Code (remember to import SwiftUI):

extension View {

    /// Navigate to a new view.
    /// - Parameters:
    ///   - view: View to navigate to.
    ///   - binding: Only navigates when this condition is `true`.
    func navigate<SomeView: View>(to view: SomeView, when binding: Binding<Bool>) -> some View {
        modifier(NavigateModifier(destination: view, binding: binding))
    }
}


// MARK: - NavigateModifier
fileprivate struct NavigateModifier<SomeView: View>: ViewModifier {

    // MARK: Private properties
    fileprivate let destination: SomeView
    @Binding fileprivate var binding: Bool


    // MARK: - View body
    fileprivate func body(content: Content) -> some View {
        NavigationView {
            ZStack {
                content
                    .navigationBarTitle("")
                    .navigationBarHidden(true)
                NavigationLink(destination: destination
                    .navigationBarTitle("")
                    .navigationBarHidden(true),
                               isActive: $binding) {
                    EmptyView()
                }
            }
        }
    }
}

回答4:

The OP has been answered multiple times here but I just wanted to also demonstrate the cool aspects of SwiftUI by showing if you have view A with data that view B will also be using, you can pass data by creating a @State in view A and declaring the same variable with @Binding declaration in view B

struct ViewA : View {
    @State var myItems: [Items]
    var body: some View {
        NavigationView {
            VStack {
                NavigationButton(destination: ViewB(items: $myItems)) {
                    Text("Go To ViewB")
                }
            }
        }
    }
}

struct ViewB : View {
    @Binding var myItems: [Items]
    var body: some View {
        NavigationView {
            List{
                ForEach(myItems.identified(by: \.self)) {
                    Text($0.itemName)
                }
            }.navigationBarTitle(Text("My Items"))
        }
    }
}

回答5:

Now we can use NavigationLink

---

File A:

struct ContentView: View {
var body: some View {
    NavigationView {
        VStack {
            Text("Hello World")
            NavigationLink(destination: secondView()) {
                Text("Hit Me!")
                    .fontWeight(.semibold)
                    .font(.title)
                    .padding()
                    .foregroundColor(.white)
                    .background(LinearGradient(gradient: Gradient(colors: [Color(.white),Color(.blue)]), startPoint: .leading, endPoint: .trailing))
                    .cornerRadius(40)
        }
      }
    }
  }
}

File B:

struct secondView: View {
var body: some View {
    VStack {
    VStack(alignment: .leading) {
        Text("Turtle Rock")
            .font(.title)
        HStack(alignment: .top) {
            Text("Joshua Tree National Park")
                .font(.subheadline)
            Spacer()
            Text("California")
                .font(.subheadline)
        }
    }
    .padding()
        Spacer()

    }
  }
}                                                                                                  

回答6:

Have to create a DetailView like LandmarkDetail() and call a NavigationButton with destination as LandmarkDetail(). Now detail view was open.

For passing values to detail screen means. by sending like below code.

struct LandmarkList: View {
    var body: some View {
        NavigationView {
            List(landmarkData) { landmark in
                NavigationButton(destination: LandmarkDetail()) {
                    LandmarkRow(landmark: landmark)
                }
            }
            .navigationBarTitle(Text("Landmarks"))
        }
    }
}

回答7:

You can no longer use NavigationButton. Instead you should use NavigationLink.

struct ContentView: View {
    var body: some View {
        NavigationView {
            NavigationLink(destination: DetailView()) {
                Text("Push new screen")
            }
        }
    }
}

回答8:

I think Jake's answer is the basic way to NextView.

And I think the way bellow is a simple, formal, and dynamic way to try, if you really need to hit a BUTTON. According to Paul Hudson's Video, from 10'00" to 12'00".

(should go to 12'00" to 15'00", if you want to go to different views by tapping different buttons.) (should go to 15'00" to 16'00", if you want to go to second view and go back automatically.) And more

And here is the code example.

import SwiftUI

struct ContentView: View {

    @State var areYouGoingToSecondView: Bool // Step 2

    var body: some View {
        NavigationView{ // Step 1

            VStack {

                // Step 3
                NavigationLink(destination: YourSecondView(), isActive: $areYouGoingToSecondView) { EmptyView() }


                Text("Hello World")

                Button(action: {
                    self.areYouGoingToSecondView = true // Step 4

                }) {
                    Text("Do Something (Go To Second View)")
                    .font(.largeTitle)
                    .fontWeight(.ultraLight)
                }
            }
        }
    }
}