In swiftui foreach onAppear Issue

Question

Here is my sample. I have a list with something to sum up. And I set up an Observe obj to store the result, trigger +1 when the subview on Appear.

class observed : ObservableObject {

@Published var listNum : Int = 0

}

struct ContentView: View {

@State private var mylist = [
    1,0,1,0,1,1
]

var body: some View {

    ForEach(mylist, id: \.self) { (value) in
        ExtractedView(value:value)
     }

    }
}


struct ExtractedView: View {

  var value : Int = 0

  @EnvironmentObject var obj : observed

  @State var listNum:String = "0"

  var body: some View {
      Text(listNum)
        .onAppear{

          if self.value != 1{
              self.obj.listNum = 0
          }else{
              self.obj.listNum += 1
          }
          self.listNum = String(self.obj.listNum)

        }
     }
  }

But the result always Upside down, not as expected.

Answer 1

Actually order of .onAppear call is undefined, so it is not clear what is expected. Anyway from what I see in provided code there might be confuse for ForEach id, `cause array value is used, but it is not unique.

Try the following

ForEach(Array(mylist.enumerated()), id: \.0) { (i, value) in
    ExtractedView(value:value)
 }