showChoicesRadioDialog<T> function Null safety

Future<T?> showChoicesRadioDialog<T>(
  1. BuildContext context,
  2. {Key? key,
  3. required Widget title,
  4. Widget? content,
  5. required List<DialogChoice<T>> choices,
  6. Widget? cancelWidget,
  7. Widget? confirmWidget,
  8. bool barrierDismissible = false,
  9. Color? barrierColor,
  10. bool useSafeArea = true,
  11. bool useRootNavigator = true,
  12. RouteSettings? routeSettings}

Displays a dialog with the choices informed in the parameter choices using radio buttons.

To close the dialog, the user must select one of the choices listed on the screen and click on the OK action, or when the Cancel button is clicked.

Example of using the dialog:

List<String> result = await showChoicesCheckBoxDialog<String>(context,
    title: Text('Select users'),
    choices: [
            icon: Icon(Icons.person),
            title: Text('Ricardo Crescenti'),
            subtitle: Text(''),
            value: 'ricardo.crescenti'),
            icon: Icon(Icons.person),
            title: Text('Ana Luiza Crescenti'),
            subtitle: Text(''),
            value: 'analuiza.crescenti'),
            icon: Icon(Icons.person),
            title: Text('Luis Otávio Crescenti'),
            subtitle: Text(''),
            value: 'luisotavio.crescenti'),

if (result != null) {
    showBasicDialog(context, title: Text('Selected users'), content: Text(result.reduce((value, element) => (value == null ? '' : value + ', ') + element)));


Future<T?> showChoicesRadioDialog<T>(BuildContext context,
    {Key? key,
    required Widget title,
    Widget? content,
    required List<DialogChoice<T>> choices,
    Widget? cancelWidget,
    Widget? confirmWidget,
    bool barrierDismissible = false,
    Color? barrierColor,
    bool useSafeArea = true,
    bool useRootNavigator = true,
    RouteSettings? routeSettings}) async {
  List<T>? result = await _showChoicesDialog<T>(context,
      title: title,
      content: content,
      choices: choices,
      cancelWidget: cancelWidget,
      okWidget: confirmWidget,
      barrierDismissible: barrierDismissible,
      barrierColor: barrierColor,
      useSafeArea: useSafeArea,
      useRootNavigator: useRootNavigator,
      routeSettings: routeSettings);

  return (result != null && result.isNotEmpty ? result[0] : null);