Flutter alert dialog

AlertDialog

import "package:flutter/material.dart";
import 'package:medium/test.dart';

void main() {
  runApp(MaterialApp(home: MyApp(), debugShowCheckedModeBanner: false));
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  @override
  Widget build(BuildContext context) {
    var raisedButton = FloatingActionButton.extended(
        backgroundColor: Colors.pink,
        icon: Icon(
          Icons.assignment_late,
          color: Colors.white,
          size: 30,
        ),
        label: Text('Show Dialog'),
        onPressed: () {
          showDialog(
            context: context,
            builder: (BuildContext context) {
              return AlertDialog(
                shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(20.0)),
                title: new Text("Alert ! ",style: TextStyle(color: Colors.red,fontWeight: FontWeight.bold),),
                content: Text("Click to continue..."),
                actions: <Widget>[
                  new FlatButton(
                    child: Icon(
                      Icons.check,
                      color: Colors.green,
                      size: 40,
                    ),
                    onPressed: () {
                      Navigator.of(context).pop();
                    },
                  ),
                ],
              );
            },
          );
        });
    return Scaffold(
      body: Container(
        color: Colors.white,
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text(
                "Dialog box in Flutter",
                style: TextStyle(
                    fontSize: 30,
                    fontWeight: FontWeight.bold,
                    color: Colors.indigo),
              ),
              SizedBox(
                height: 30,
              ),
              Container(child: raisedButton),
            ],
          ),
        ),
      ),
    );
  }
}