SwiftUI:how to get the secondView showed in full screen when I transfer to secondView from firstView

You should better choose the right topic area: SwiftUI

`sheet` does not seem to provide much option to customize the presented view.

One way to present a view in full screen, is to declare the second view inside the first view, overlapping.

Try something like this:

import SwiftUI

struct ContentView: View {
    @State var showsecondView: Bool = false
    
    var body: some View {
        ZStack {
            Button(action: {
                self.showsecondView.toggle()
            }) {
                Text("firstView")
            }
            if self.showsecondView {
                SecondView(showsecondView: self.$showsecondView)
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
                    .background(Color.red)
                    .animation(.easeInOut)
                    .transition(.move(edge: .bottom))
            }
        }
    }
}

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

struct SecondView: View {
    @Binding var showsecondView: Bool
    
    var body: some View {
        VStack {
            Button(action: {
                self.showsecondView = false
            }) {
                Text("dismiss")
            }
            
            Text("secondView")
        }
    }
}

thank you for your code ,it worked!

I want to ask another question: I transfered the view from the FirstView to SecondView, from SecondView to ThirdView.How to transferthe view from ThirdView to FirstView?

here is my code:

import SwiftUI

struct ContentView: View {

     @State var showSecondView:Bool = false
   var body: some View {
       
            
                
                
                ZStack{
                    Button(action: {
                        self.showSecondView.toggle()
                    }) {
                        Text("showSecondView")
                    }
                   if self.showSecondView {
                        SecondView(showSecondView: self.$showSecondView)
                            .frame(maxWidth: .infinity, maxHeight: .infinity)
                            .background(Color.red)
                            .animation(.easeInOut)
                            .transition(.move(edge: .bottom))
                    }
                }
                
            
        }
}
        struct SecondView: View {
            @Binding var showSecondView:Bool
            @State var showThirdView:Bool = false
            var body: some View {
                ZStack{
                    Button(action: {
                       
                        self.showThirdView.toggle()
                    }) {
                        Text("showThirdView")
                    }
                    
                    if self.showThirdView {
                        ThirdView(showThirdView: self.$showThirdView)
                            .frame(maxWidth: .infinity, maxHeight: .infinity)
                            .background(Color.yellow)
                            .animation(.easeInOut)
                            .transition(.move(edge: .bottom))
                    }
                
                
                }
            }
        }
        struct ThirdView: View {
            
            @Binding var showThirdView:Bool
            
            
            var body: some View {
                ZStack{
                    Button(action: {
                        
                    }) {
                        Text("showFirstView")
                    }
                    
                }
            }
        }
struct ContentView_Previews: PreviewProvider {
   static var previews: some View {
        ContentView()
    }
}

How to transferthe view from ThirdView to FirstView?

Even in a classic environment using UIKit, such transition will make an infinite loop, and causes infinite memory consumption.

App does not manage views like web browser, go-only transitions will corrupt eventually.

Better find a way to return to the FirstView.