SwiftUI之页面跳转

1.更改根控制器页面：

Button.init("返回") {

            let screnDelegate: UIWindowSceneDelegate? = {

                            var uiScreen: UIScene?

                            UIApplication.shared.connectedScenes.forEach { (screen) in

                                uiScreen = screen

                            }

                            return (uiScreen?.delegate as? UIWindowSceneDelegate)

                        }()

             screnDelegate?.window!?.rootViewController  = UIHostingController(rootView: HomeView());

            或者

            UIApplication.shared.windows.first?.rootViewController  = UIHostingController(rootView: HomeView())

        }

2.push跳转

import SwiftUI

struct HomeView:View {

    var body: some View{

        return List{

                    ForEach(0..<3, id: \.self) { index in

                        if index==0{
                  NavigationLink(destination: one.init(name: "", age: 1)){

                                Text("\(index)")
                          }

                        }

                        if index==1{

                            NavigationLink(destination: Two()){

                                Text("\(index)")

                            }
                        }

                       }

                   }

      }

}

 push/pop:跳转的时候带参数，控制pop返回

import SwiftUI

struct HomeView:View {
    @State var isShow = false
    var body: some View{
       //isActive是控制是否自动跳转，false不自动跳转,跳转到下一个页面后isShow就变成了true
        NavigationLink(destination: one(showing:$isShow), isActive: self.$isShow) {
                Text("one")
                   }
            
        }
   }

pop返回：

mport SwiftUI

struct one: View {
  
    @Binding var showing :Bool
    var body: some View {
        Button("点击返回") {
                   self.showing = false//这个控制pop返回
               }
    }
    
}

pop到根视图：在SwiftUI下实现popToRootViewController()返回根视图 - 知乎

present:（fullScreenCover）

import SwiftUI

struct HomeView:View {
    @State var isPresented = false
    var body: some View{
        Button("present"){
            self.isPresented = true
        }.fullScreenCover(isPresented: $isPresented) {
            print("消失")
        } content: {
            Two()
        }
   }
}

import SwiftUI

struct Two: View {
    @Environment(\.presentationMode) var presentationModess
    var body: some View {
        Text("Hello,two")
        Button("返回"){
            self.presentationModess.wrappedValue.dismiss()//返回的方法
        }
    }
}

sheet:（和present类似，只需改变fullScreenCover为sheet）

import SwiftUI

struct HomeView:View {
    @State var isPresented = false
    var body: some View{
        Button("sheet"){
            self.isPresented = true
        }.sheet(isPresented: $isPresented) {//这个是页面消失后的回调
            print("消失")
        } content: {
            Two()
        }

   }
}

   present返回

import SwiftUI

struct Two: View {
//该视图将创建一个名为presentationMode的属性，该属性附加到存储在应用程序环境中的演示模式变量中
    @Environment(\.presentationMode) var presentationModess
    var body: some View {
        Text("Hello,two")
        Button("返回"){
//需要在其中添加wrapdValue，因为presentationMode实际上是一个绑定，因此它可以由系统自动更新——我们需要在其中进行解包以检索实际的呈现方式，以关闭视图。
            self.presentationModess.wrappedValue.dismiss()//返回的方法
        }
    }
}

alert:提示框,最多两个按钮

import SwiftUI

struct HomeView:View {
    @State var showAlert = false
    var body: some View{
        Button("alert"){
            self.showAlert = true
        }.alert(isPresented: $showAlert){
//         Alert(title: Text("one"), message: Text("two"), dismissButton: .default(Text("ok")))
            return Alert(title: Text("one"), message: Text("one"), primaryButton: .cancel(Text("取消"), action: {
                print("取消")
            }), secondaryButton:.default(Text("确定"), action: {
                print("确定")
            }))
        }
   }
}

actionsheet:提示框，可以有多个按钮

import SwiftUI

struct HomeView:View {
    @State var isPresented = false
    var body: some View{
        Button("present"){
            self.isPresented = true
        }.actionSheet(isPresented: $isPresented) {
            ActionSheet(title: Text("Change background"), message: Text("Select a new color"), buttons: [
                .default(Text("Red")) { print("Red") },
                .default(Text("Green")) { print("green") },
                .default(Text("Blue")) {print("blue") },
                .cancel()
            ])
        }
   }
}

跳转到safari浏览器：必须要加上http

Link(destination: URL(string: "https://www.baidu.com")!) {
    Text("百度搜索")
}