flutter screen orientation portrait only code example

Example 1: flutter portrait only

// This will works always for lock screen Orientation.
void main() {
  WidgetsFlutterBinding.ensureInitialized();
  SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp])
    .then((_) {
      runApp(new MyApp());
    });
}

Example 2: flutter display widget based on device orientation

build(BuildContext context) {
    final isLandscape = MediaQuery.of(context).orientation ==
        Orientation.landscape; // check if the orientation is landscape
        
        
        // further down your code you can use 'if' or 'ternary' or both
        if (!isLandscape) txListWidget,
            if (isLandscape)
            _ternaryCondition ? _showFirstWidget : _showSecondWidget
            // the above widgets would be in a 'Row' or 'Column'
        }