如何在flutter中为对话框添加圆形边框？

import 'package:flutter/material.dart';

class CustomDialog extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Dialog(
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10.0),
      ),
      child: Container(
        padding: EdgeInsets.all(16.0),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(
              '对话框标题',
              style: TextStyle(
                fontWeight: FontWeight.bold,
                fontSize: 18.0,
              ),
            ),
            SizedBox(height: 10.0),
            Text('对话框内容'),
            SizedBox(height: 10.0),
            RaisedButton(
              child: Text('确定'),
              onPressed: () {
                // 点击确定按钮的回调逻辑
              },
            ),
          ],
        ),
      ),
    );
  }
}

// 在需要显示对话框的地方调用 showDialog 方法
void showCustomDialog(BuildContext context) {
  showDialog(
    context: context,
    builder: (BuildContext context) {
      return CustomDialog();
    },
  );
}