Flutter ダイアログを表示する実装方法を解説

何も考えないなら以下をコピペして呼び出す。　

static void showDialog(BuildContext context, String title, String content, String positiveButton, String negative,
      {VoidCallback? onPositiveButtonPressed, VoidCallback? onNegativeButtonPressed}) {
      showDialog<int>(
        context: context,
        barrierDismissible: true, // キャンセル
        builder: (BuildContext context) {
          return AlertDialog(
              title: Text(title),
              content: Text(content),
              actions: [
                TextButton(child: Text(positiveButton), onPressed: onPositiveButtonPressed),
                TextButton(child: Text(negative), onPressed: onNegativeButtonPressed)
              ]);
        });
}