POSTED BY
2023-09-26

以下のように、上位からBinding変数を受け取る子Viewの初期化時に起こるエラー。

struct ContentView: View {
    @Binding var isActive:Bool
    init(isActive:Binding) {
        self.isActive = isActive
        if self.isActive {
            print("acvite")
        }
    }
    var body: some View {
        Text("Hello World!)
    }
}
struct ContentView_Previews: PreviewProvider {
  static var previews: some View {
    @State var isActive = true
    ContentView(isActive:$isActive)
  }
}

Cannot assign value of type 'Binding<Bool>' to type 'Bool'

Binding変数を受け取る時は、_をつければ良いらしい。以下のようにする。

struct ContentView: View {
    @Binding var isActive:Bool
    init(isActive:Binding) {
        self._isActive = isActive
        if self.isActive {
            print("acvite")
        }
    }
    var body: some View {
        Text("Hello World!)
    }
}
struct ContentView_Previews: PreviewProvider {
  static var previews: some View {
    @State var isActive = true
    ContentView(isActive:$isActive)
  }
}