swift picker not selecting item - swift

Question

I have a short array of items that I want to display in a segmented picker. I'm passing the selected item (0, by default). The picker displays, but no item is selected, and the picker is unresponsive to clicks (in the simulator). I have a very similar picker that uses percentage values, and it works correctly. I am guessing that the issue has to do with the closure that I'm passing to the ForEach loop, but I am unclear on what syntax I should be using, if that is in fact the issue.
The code is as follows:
#State private var originalUnit = 0
let sourceUnits = ["meters","kilometers","feet","yards","miles"]
var body: some View {
NavigationView {
Form {
Section {
Picker("Unit", selection $originalUnit) {
ForEach(sourceUnits, id: \.self {
Text($0)
}
} .pickerStyle(.segmented)
} header: {
Text("Choose Unit")
}
} .navigationTitle("MyApp")
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Any insights on this would be appreciated. Thanks in advance!

Answer 1

You have a type mismatch between your originalUnit (Int) and your sourceUnits (String). Your selection needs to match the type.
struct ContentView: View {
#State private var originalUnit = "meters" //<-- Here
let sourceUnits = ["meters","kilometers","feet","yards","miles"]
var body: some View {
NavigationView {
Form {
Section {
Picker("Unit", selection: $originalUnit) {
ForEach(sourceUnits, id: \.self) {
Text($0)
}
} .pickerStyle(.segmented)
} header: {
Text("Choose Unit")
}
} .navigationTitle("MyApp")
}
}
}
If, for some reason, you really needed originalUnit to be an Int, you could use enumerated (normally not the most efficient method for large collections in a ForEach, but that'll be inconsequential for something this small) so that the id is the index and matches the type (Int) of originalUnit:
struct ContentView: View {
#State private var originalUnit = 0
let sourceUnits = ["meters","kilometers","feet","yards","miles"]
var body: some View {
NavigationView {
Form {
Section {
Picker("Unit", selection: $originalUnit) {
ForEach(Array(sourceUnits.enumerated()), id: \.0) { //<-- .0 is the index (Int)
Text($0.1) //<-- .1 is the original item String
}
} .pickerStyle(.segmented)
} header: {
Text("Choose Unit")
}
} .navigationTitle("MyApp")
}
}
}

Answer 2

You can set tag for your picker's row. Tag is any hashable type.
Refer this code work with any type of object for selection
struct TestView: View {
#StateObject var viewModel = TestViewModel()
var body: some View {
VStack {
Text(viewModel.selectedItem.title)
Picker("Select item", selection: $viewModel.selectedItem) {
ForEach(viewModel.items) { makeRowForItem($0) }
}
}
}
#ViewBuilder
func makeRowForItem(_ item: Item) -> some View {
Text(item.title).tag(item)
}
}
struct Item: Identifiable, Hashable {
var id = UUID().uuidString
var title = "Untitled"
func hash(into hasher: inout Hasher) {
hasher.combine(id)
}
}
class TestViewModel: ObservableObject {
#Published var selectedItem: Item
#Published var items: [Item]
init() {
let list = (1..<10).map { Item(title: "Untitled \($0)") }
items = list
selectedItem = list.first!
}
}