Having trouble centering a row widget - flutter

Question

I have a Row widget on the bottom of the page that I can't center. I've tried all the mainAxisAlignment's and crossAxisAlignment's there are, as well as wrapping it in an Align widget and setting alignment to alignment.center and it's still on the left edge of the page. I've tried everything and am really stuck. Any help would be appreciated.
The Page (Updated)
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.lightBlue,
centerTitle: true,
elevation: 5,
title: Text("Pathomatic")),
body: Container(
decoration: new BoxDecoration(color: Colors.black),
child: SafeArea(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Expanded(
flex: 2,
child: new Stack(
children: <Widget>[
new Container(
alignment: Alignment.center,
child: _cameraPreviewWidget(context),
),
new Align(
alignment: Alignment.center,
child: GestureDetector(
child: Stack(children: <Widget>[
Positioned(
top: yPosition,
left: xPosition,
child: Container(
// padding: EdgeInsets.only(top: 200.0, left: 20.0),
height: MediaQuery.of(context).size.height / 3,
width: MediaQuery.of(context).size.width / 3,
child:
Image.asset('assets/images/crosshair.png'),
),
),
]),
onPanUpdate: (tapInfo) {
setState(() {
xPosition += tapInfo.delta.dx;
yPosition += tapInfo.delta.dy;
});
}),
),
],
),
),
SizedBox(height: 5),
Row(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: [
Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
_cameraTogglesRowWidget(),
_mlTextWidget(),
],
),
_captureControlRowWidget(context),
//SizedBox(width: 50),
],
),
SizedBox(height: 5),
],
),
),
),
);
}

Answer 1

This is usually because the widget you are trying to center is actually stretching its container. Since it's the size of the screen, it's contents stick to the left. You should use the Flutter Inspector with select widget mode to actually see how large your row is. Then everything will make much more sense.
In your code, your Row is stretching. Try
Row(mainAxisSize: MainAxisSize.min
This should make it not grow. Alternatively, you can keep the row large but make it center its children:
Row(mainAxisAlignment: MainAxisAlignment.Center
Of course, with this approach its children will get close to each other in the center. You can use a SizedBox between them, or use some other way of spacing them apart.