Flutter android及ios强制竖屏/横屏

在main.dart内设置即可

void main(){
  WidgetsFlutterBinding.ensureInitialized();  		//不加这个强制横/竖屏会报错
  SystemChrome.setPreferredOrientations([     // 强制竖屏
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown
  ]);
  SystemChrome.setPreferredOrientations([ 	 //强制横屏
    DeviceOrientation.landscapeLeft,
    DeviceOrientation.landscapeRight
  ]);
  runApp(new MyApp());
}