Expanded widget throws "RenderBox was not laid out" exception - flutter

Question

Hi I'm new to Flutter and I got in trouble with the exception "RenderBox was not laid out".
I'm trying to create MyDialog which is an extension of the built-in dialog.
It can be injected contents from other widget. And I wanna place Expanded widget wrapping Text widget as the contents so that all text can be seen with line breaks.
I intent the contents show like this:
This is my MyDialog widget.
class MyDialog extends StatelessWidget {
String label;
Widget contents;
const MyDialog({required this.label, required this.contents, Key? key}) : super(key : key)
#override
Widget build(BuildContext context) {
return MyButtonTip( // This is an extension of outlined button.
label : label,
onPressed : () {
showDialog(
context : context,
builder : (BuildContext context) => AlertDialog(
insetPadding : const EdgeInsets.all(15),
content : SizedBox(
width : MediaQuery.of(context).size.width,
child : contents
)
)
);
}
);
}
}
And this is the widget that uses MyDialog.
...
MyDialog(
label : 'Profile',
contents : SizedBox(
child : Stack(
children : [
Column(
children : [
Row(
children : [
Column(
crossAxisAlignment : CrossAxisAlignment.end,
children : const [
Text('name'),
Text('nickname')
]
),
const SizedBox(width : 10),
Column(
crossAxisAlignment : CrossAxisAlignment.start,
children : [
Text(name),
Expanded(
child : Text(nickname)
)
]
)
]
)
]
)
]
))
)
);
...
(I'm using Stack for aiming something different, so please don't care about it.)
I would like to know the correct solution, as I have encountered this exception many times before and each time it has somehow been resolved. Please let me know in detail.
Thanks,
PS. console:

Answer 1

As my opinion you placed widget wrong please try with below code :
MyDialog(
label : 'Profile',
contents : Column(children: [
Row(children: const [
Text('name : '),
Text("hello"),
]),
const SizedBox(width: 10),
Row(crossAxisAlignment: CrossAxisAlignment.start, children: const [
Text('taro yamuda : '),
Expanded(
child: Text(
"someting sometingsometingsometingsometingsometingsometingsometingsometingsometingsometingsometingsometing",
style: TextStyle(),
),
)
])
]);
}