Flutter：带有 CupertinoNavigationBar 后退按钮的警报对话框

Question

颤动问题：我正在尝试在我的 Cupertino 导航栏后退按钮上实现一个警告对话框，但我想我不知道当我不使用自定义后退按钮时它会如何工作。

有人知道吗？

class ameriCares extends StatelessWidget {
const ameriCares({Key? key}) : super(key: key);

@override
Widget build(BuildContext context) {
return CupertinoPageScaffold(
  navigationBar: CupertinoNavigationBar(middle: Text("Americares")),  //i want to add the alert dialog here on the back button
  child: SafeArea(
    child: WebView(
      initialUrl: AppLocalizations.of(context)!.americares,
      javascriptMode: JavascriptMode.unrestricted,
    ),
    //bottomNavigationBar: CustomBottomNavBar(selectedMenu: MenuState.give),
  ),
);
}
}

万分感谢

Answer 1

尝试向 CupertinoNavigationBar - GestureDetector 添加一个带图标的前导参数。

Widget build(BuildContext context) {
  return CupertinoPageScaffold(
    navigationBar: CupertinoNavigationBar(
      middle: Text(
        "Americares",
      ),
      leading: GestureDetector(
        onTap: () {
          showDialog<void>(
            context: context,
            barrierDismissible: false, // user must tap button!
            builder: (BuildContext context) {
              return AlertDialog(
                title: const Text('AlertDialog Title'),
                content: SingleChildScrollView(
                  child: ListBody(
                    children: const <Widget>[
                      Text('This is a demo alert dialog.'),
                      Text('Would you like to approve of this message?'),
                    ],
                  ),
                ),
                actions: <Widget>[
                  TextButton(
                    child: const Text('Approve'),
                    onPressed: () {
                      Navigator.of(context).pop();
                    },
                  ),
                ],
              );
            },
          );
        },
        child: Icon(
          CupertinoIcons.left_chevron,
          color: CupertinoColors.black,
        ),
      ),
    ), //i want to add the alert dialog here on the back button
    child: SafeArea(
      child: WebView(
        initialUrl: AppLocalizations.of(context)!.americares,
        javascriptMode: JavascriptMode.unrestricted,
      ),
      //bottomNavigationBar: CustomBottomNavBar(selectedMenu: MenuState.give),
    ),
  );
}

Flutter：带有 CupertinoNavigationBar 后退按钮的警报对话框

Flutter: Alert Dialog with CupertinoNavigationBar back button

flutter

flutter-alertdialog