当我将纵向旋转为横向时，flutter应用程序为空白

<activity
    android:name=".MainActivity"
    android:configChanges="orientation|screenSize|keyboardHidden">
</activity>

<key>UISupportedInterfaceOrientations</key>
<array>
    <string>UIInterfaceOrientationPortrait</string>
    <string>UIInterfaceOrientationLandscapeLeft</string>
    <string>UIInterfaceOrientationLandscapeRight</string>
</array>

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: OrientationBuilder(
        builder: (context, orientation) {
          return orientation == Orientation.portrait
              ? PortraitLayout()
              : LandscapeLayout();
        },
      ),
    );
  }
}

class PortraitLayout extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Portrait')),
      body: Center(child: Text('This is portrait mode')),
    );
  }
}

class LandscapeLayout extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Landscape')),
      body: Center(child: Text('This is landscape mode')),
    );
  }
}