Widget DataTable with border radius.

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: TableData(),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Holi DataTable'),
      ),
      body: Container(
        color: Colors.pink[100],
        child: Center(
          child: Column(children: [
            SizedBox(
              height: 100,
              width: 100,
            ),
            ClipRRect(
              borderRadius: BorderRadius.circular(10),
              child: Container(
                width: 350,
                height: 180,
                decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.circular(10),
                  //boxShadow: [
                  //  BoxShadow(
                  //    color: Colors.black
                  //        .withOpacity(1), // changes position of shadow
                  //  ),
                  //],
                ),
                child: DataTable(
                  columnSpacing: 90,
                  dataRowHeight: 30,
                  horizontalMargin: 15,
                  headingRowColor: MaterialStateProperty.resolveWith<Color>(
                      (Set<MaterialState> states) {
                    return Color(0xFFF8F9FA);
                  }),
                  columns: [
                    DataColumn(label: Text('Productos')),
                    DataColumn(label: Text('Cantidad'))
                  ],
                  rows: [
                    DataRow(
                      cells: [
                        DataCell(Text('Champan Baron B')),
                        DataCell(Text('2')),
                      ],
                    ),
                    DataRow(
                      cells: [
                        DataCell(Text('Cerveza Miller')),
                        DataCell(Text('4')),
                      ],
                    ),
                    DataRow(
                      cells: [
                        DataCell(Text('Cerveza Patagonia')),
                        DataCell(Text('4')),
                      ],
                    ),
                    DataRow(
                      cells: [
                        DataCell(Text('Cerveza Imperial')),
                        DataCell(Text('2')),
                      ],
                    ),
                  ],
                ),
              ),
            ),
          ]),
        ),
      ),
    );
  }
}