首先你需要更新你的flutter版本到3.13或更高版本，因为AlertDialog.adaptive特性是3.13自带的。3.13框架改进-https://medium.com/@ak187429/flutter-3-13-framework-improvements-41be37e925d8。在写作上，作者提到了AlertDialog. adaptive。这里有AlertDialog.adaptive的示例代码

floatingActionButton: FloatingActionButton.extended(
        label: const Text('Show Alert Dialog Adaptive'),
        onPressed: () async {
          final response = await showAdaptiveDialog<bool>(
            context: context,
            builder: (context) {
              return AlertDialog.adaptive(
                content: const Text('This is an adaptive alert dialog'),
                actions: [
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(false),
                    child: const Text('Cancel'),
                  ),
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(true),
                    child: const Text('OK'),
                  ),
                ],
              );
            },
          );
          print(response);
        },
      ),

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我的Flutter版本- 3.13.8，我的 dart 版本- 3.1.4，这段代码在我的电脑上工作：）

我运行你的代码什么我没有我声明一个函数showDialoog这里是代码和结果是在截图其工作罚款

showDialoog(BuildContext context)async{
final endExam = await showDialog<bool>(
  context: context,
  builder: (context) {
    return AlertDialog.adaptive(
      title: const Text("Submit Exam"),
      content: Text(
        'You have time left.\n'
        'Are you sure you want to submit?',
      ),
      actions: [
        TextButton(
          onPressed: () {
            Navigator.pop(context, false);
          },
          child: const Text("Cancel"),
        ),
        TextButton(
          onPressed: () {
            Navigator.pop(context, true);
          },
          child: const Text(
            "Submit",
            style: TextStyle(color: Colors.red),
          ),
        ),
      ],
    );
  },
);
}```

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