SwiftUI 如何在关闭时将数据传递到上一个屏幕

Question

我想将关闭 presentViewController 的数据传递到上一个屏幕。在这里，我想使用块将数据作为 UIKitApp 传递到上一个屏幕。但我不知道要传递数据。 options 我们必须向后传递的数据是什么？

struct ContentView: View {
    @State var showModel = false
    var body: some View {
        VStack {
            Button(action: {
                showModel.toggle()
            }, label: {
                Text("Show filters")
            }).sheet(isPresented: $showModel, content: {
                FilterView()
            })
        }
    }
}

struct FilterView: View {
    @Environment(\.presentationMode) var presentationMode

    var onDismiss: ((_ model: Filter) -> Void)?

    var body: some View {
        
        VStack {
            Button(action: {
                // Pass data from here to ContentView
                let filter = Filter(fromDate: "10/07/2021", toDate: "12/07/2021")
                onDismiss?(filter)
                presentationMode.wrappedValue.dismiss()
            }, label: {
                Text("Applay Filters")
            }).padding()
        }.padding()
    }
}

struct Filter {
    var fromDate: String
    var toDate: String
}

Answer 1

您可以为此使用 @Binding（或使用 MVVM 设计模式 @StateObject、@ObservedObject、@Environmentobject 和 @ObservableObject）

下面的代码是使用@Binding 的示例。

Added/Edited 行

Text("\(filter.fromDate) and \(filter.toDate)") // to see the changed values

@State var filter = Filter(fromDate: "", toDate: "") // in ContentView

@Binding var filter: Filter // in FilterView

FilterView(filter: $filter) // $ used for @Binding parameter

完整代码

struct ContentView: View {
    @State var showModel = false
    @State var filter = Filter(fromDate: "", toDate: "")
    
    var body: some View {
        VStack {
            Text("\(filter.fromDate) and \(filter.toDate)")
            Button(action: {
                showModel.toggle()
            }, label: {
                Text("Show filters")
            }).sheet(isPresented: $showModel, content: {
                FilterView(filter: $filter)
            })
        }
    }
}

struct FilterView: View {
    @Environment(\.presentationMode) var presentationMode

    var onDismiss: ((_ model: Filter) -> Void)?
    @Binding var filter: Filter

    var body: some View {
        
        VStack {
            Button(action: {
                // Pass data from here to ContentView
                filter = Filter(fromDate: "10/07/2021", toDate: "12/07/2021")
                onDismiss?(filter)
                presentationMode.wrappedValue.dismiss()
            }, label: {
                Text("Applay Filters")
            }).padding()
        }.padding()
    }
}

struct Filter {
    var fromDate: String
    var toDate: String
}

SwiftUI 如何在关闭时将数据传递到上一个屏幕

SwiftUI how to pass data to previous screen on dismiss

ios

swift

swiftui

swiftui-form