Flutter: ListView in a SimpleDialog

Just wrap ListView.builder in a Container with a specific height and width.

Widget setupAlertDialoadContainer() {
  return Container(
    height: 300.0, // Change as per your requirement
    width: 300.0, // Change as per your requirement
    child: ListView.builder(
      shrinkWrap: true,
      itemCount: 5,
      itemBuilder: (BuildContext context, int index) {
        return ListTile(
          title: Text('Gujarat, India'),
        );
      },
    ),
  );
}

And call the above method in showDialog.

showDialog(
    context: context,
    builder: (BuildContext context) {
      return AlertDialog(
        title: Text('Country List'),
        content: setupAlertDialoadContainer(),
      );
    });

EDITED:

You can go with @Rap's comment too.

Wraping the ListView in a Container and giving it a width: double.maxFinite, solves the problem with iOS/Android having trouble with ListView inside a dialog:

showDialog(
   context: context,
   builder: (BuildContext context) {
      return AlertDialog(
         content: Container(
            width: double.maxFinite,
            child: ListView(
               children: <Widget>[]
            ),
         ),
      );
   }
);

In the case of a ListView inside a Column that is inside an AlertDialog:

showDialog(
   context: context,
   builder: (BuildContext context) {
      return AlertDialog(
         content: Container(
            width: double.maxFinite,
            child: Column(
               mainAxisSize: MainAxisSize.min,
               children: <Widget>[
                  Expanded(
                     child: ListView(
                        shrinkWrap: true,
                        children: <Widget>[]
                     )
                  )
               ]
            ),
         ),
      );
   }
);