Passing a value to a text box in navigation link view-CodePudding

I am trying to pass a value from a text box in my first view to a text box in my second view.

struct FirstView: View {
@State private var inputTextValue = ""
var body: some View {        
    NavigationView{
        VStack {
            TextField("",text: $inputTextValue)
                .frame(width: 200, height: 30, alignment: .center)
                .border(.gray)
            NavigationLink(destination: {SecondView(incomingTextFieldvalue: inputTextValue)}, label: {Text("To second view")})
        }
    }
}


struct SecondView: View {
var incomingTextFieldvalue: String
@State var textFieldValue = "Initial Value in view 2"
var body: some View {
    VStack {
        Spacer()
        TextField("",text: $textFieldValue)
            .frame(width: 200, height: 30, alignment: .center)
            .border(.gray)
        Spacer()
        Text("Incoming value: \(incomingTextFieldvalue)")
        Text("This value: \(textFieldValue)")
        
        Spacer()
    }
}

So, what I want exactly is that the text box in the second view has the passed value filled in initially.

I have tried various solutions, but have not been able to get the solution that I need. Please let me know if I need to provide more info.

CodePudding user response：

We can set incoming value to internal in onAppear, like

VStack {
    Spacer()
    TextField("",text: $textFieldValue)
        .frame(width: 200, height: 30, alignment: .center)
        .border(.gray)
    Spacer()
    Text("Incoming value: \(incomingTextFieldvalue)")
    Text("This value: \(textFieldValue)")

    Spacer()
}
.onAppear { textFieldValue = incomingTextFieldvalue }   // << here !!

Tested with Xcode 13.4 / iOS 15.5

*(of course if you don't want to share them, which is unclear)

CodePudding user response：

You need to use @Binding like so:

In FirstView:

struct FirstView: View {
    @State private var inputTextValue = ""
    var body: some View {
        NavigationView{
            VStack {
                TextField("",text: $inputTextValue)
                    .frame(width: 200, height: 30, alignment: .center)
                    .border(.gray)
                NavigationLink(destination: SecondView(incomingTextFieldvalue: $inputTextValue), label: {Text("To second view")})
            }
        }
    }
}

In SecondView:

struct SecondView: View {
    @State var textFieldValue = "Initial Value in view 2"
    @Binding var incomingTextFieldvalue: String
    var body: some View {
        VStack {
            Spacer()
            TextField("",text: $incomingTextFieldvalue)
                .frame(width: 200, height: 30, alignment: .center)
                .border(.gray)
            Spacer()
            Text("Incoming value: \(incomingTextFieldvalue)")
            Text("This value: \(textFieldValue)")
            Spacer()
        }
    }
}

Also note that when passing a destination for the NavigationLink you don't need to use {}