Flutter set widget position exactly center of the screen - flutter

Question

I want to put a container widget in the middle of the device screen. However, since I used the SizedBox() and SvgPicture.asset() widgets before that, the container does not come right in the middle of the device. How can I do this?
This is my code:
class CenterWidget extends StatefulWidget {
const CenterWidget({Key? key}) : super(key: key);
#override
_CenterWidgetState createState() => _CenterWidgetState();
}
class _CenterWidgetState extends State<CenterWidget> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 30),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisSize: MainAxisSize.max,
children: [
const SizedBox(height: 56),
SvgPicture.asset(ImageConstants.instance.logoSvg,
width: (MediaQuery.of(context).size.width - 60) / 2),
Expanded(
child: Center(
child: Container(
color: Colors.red,
width: 100,
height: 100,
),
),
),
],
),
),
),
);
}
}

Answer 1

Use a top center aligned stack, and put the widget you want to be centered within a Positioned.fill widget. You can put the spacer and logo in their own column to keep them arranged vertically:
class _CenterWidgetState extends State<CenterWidget> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 30),
child: Stack(
alignment: Alignment.topCenter,
children: [
Column(
children: [
const SizedBox(height: 56),
SvgPicture.asset(ImageConstants.instance.logoSvg,
width: (MediaQuery.of(context).size.width - 60) / 2),
],
),
Positioned.fill(
child: Center(
child: Container(
color: Colors.red,
width: 100,
height: 100,
),
),
),
],
),
),
),
);
}
}