SwiftUI制作View可嵌套组件

Posted 2021-03-01 liuxiaokun

SwiftUI制作View可嵌套组件

• 了解嵌套组件制造原理

• 制作一套嵌套组件

• 掌握配置嵌套组件的preview的方法

• 如何初始化嵌套参数

• 基础构造

struct ENavigationView<Content: View>: View {

    let viewBuilder: () -> Content

    var body: some View {
        NavigationView {
            VStack {
                viewBuilder()
                    .navigationBarTitle("My App")
            }
        }
    }

}

struct ENavigationView_Previews: PreviewProvider {
    static var previews: some View {
        ENavigationView {
            Text("Preview")
        }
    }
}

struct ContentView: View {

    var body: some View {
        ENavigationView {
            Text("My Text")
        }
    }

}

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

• 初始化参数

struct ENavigationView<Content: View>: View {

    let viewBuilder: () -> Content
    @Binding var oneFlag:Int
init(oneFlag:Int,, @ViewBuilder content: @escaping () -> Content)
    {
        self.oneFlag = oneFlag
        self.viewBuilder = content
    }
    var body: some View {

        NavigationView {
            VStack {
                viewBuilder()
                    .navigationBarTitle("My App")
            }
        }
    }

}

struct ENavigationView_Previews: PreviewProvider {
    static var previews: some View {
        ENavigationView {
            Text("Preview")
        }
    }
}

struct ContentView: View {
@State var oneFlag = 1
    var body: some View {
        ENavigationView(oneFlag:self.oneFlag) {
            Text("My Text")
        }
    }

}

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