How to detect orientation change in layout in Flutter?

问题

How to find out Orientation is portrait or landscape in Flutter

if(portrait){
  return ListView.builder()
}else{
  return GridView.count()
}

回答1:

In order to determine the Orientation of the screen, we can use the OrientationBuilder Widget. The OrientationBuilder will determine the current Orientation and rebuild when the Orientation changes.

new OrientationBuilder(
  builder: (context, orientation) {
    return new GridView.count(
      // Create a grid with 2 columns in portrait mode, or 3 columns in
      // landscape mode.
      crossAxisCount: orientation == Orientation.portrait ? 2 : 3,
    );
  },
);

you can find the complete example here: https://flutter.io/cookbook/design/orientation/

回答2:

You can use MediaQuery to check orientation:

var isPortrait = MediaQuery.of(context).orientation == Orientation.portrait

回答3:

it's quite easy

if (MediaQuery.of(context).orientation == Orientation.portrait){
    // is portrait
}else{
// is landscape
}

来源：https://stackoverflow.com/questions/50815014/how-to-detect-orientation-change-in-layout-in-flutter