switchToPortrait static method
切换到竖屏模式
Implementation
static Future<void> switchToPortrait() async {
  await SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp, // 正常竖屏
    DeviceOrientation.portraitDown, // 倒置竖屏
  ]);
}切换到竖屏模式
static Future<void> switchToPortrait() async {
  await SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp, // 正常竖屏
    DeviceOrientation.portraitDown, // 倒置竖屏
  ]);
}