如何在Flutter中创建一个加载屏幕？

import 'package:flutter/material.dart';
import 'package:flutter_spinkit/flutter_spinkit.dart';

class LoadingScreen extends StatefulWidget {
  @override
  _LoadingScreenState createState() => _LoadingScreenState();
}

class _LoadingScreenState extends State<LoadingScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            SpinKitFadingCircle(
              color: Colors.blue,
              size: 50.0,
            ),
            SizedBox(height: 20.0),
            Text(
              '加载中...',
              style: TextStyle(fontSize: 16.0),
            ),
          ],
        ),
      ),
    );
  }
}

Navigator.push(
  context,
  MaterialPageRoute(builder: (context) => LoadingScreen()),
);