How add rounded border and gradient color to the flutter button

home_screen.dart

import 'package:flutter/material.dart';

class WelcomeScreen extends StatefulWidget {
  @override
  _WelcomeScreenState createState() => _WelcomeScreenState();
}

class _WelcomeScreenState extends State<WelcomeScreen> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            // ignore: deprecated_member_use
            SizedBox(
              width: 200,
              // ignore: deprecated_member_use
              child: RaisedButton(
                padding: EdgeInsets.zero,
                  onPressed: () {print('Button Work !');},
                  shape: StadiumBorder(),
                  child: Container(
                    padding: EdgeInsets.symmetric(vertical: 10.0, horizontal: 53.0),
                    decoration: ShapeDecoration(
                        gradient: LinearGradient(colors: [Colors.lightBlue, Colors.deepPurpleAccent]),
                      shape: StadiumBorder()
                    ),
                    child: Text(
                      'Get Started',
                      style: TextStyle(
                        fontSize: 18.0, fontWeight: FontWeight.w400
                      ),
                    ),
                  ),
              ),
            )
          ],
        ),
      ),
    );
  }
}