How to implement a flutter layout more easily？ - layout

Question

I have a layout effect, I don't know how to implement it more easily? I have six or N child widgets, placed in a parent widget with two child widgets per row, each widget is 50% the width of the parent widget and height is the height /rows of the parent widget.
I can use column, row expanded to do this, but I don't think it's simple enough.If my child widgets are intermediate, I don't know how to create them dynamically.
The layout effect what I want to achieve:
The way I want to do it is the following pseudocode
I can do it in Android and iOS, but I don't know how to do it with flutter.
var parentWidget = Widget()
for (var i = 0; i < 6; i++) {
var child = Widget()
parentWidget.add(child)
}
The Flutter is implemented as follows. I can use column,row expanded to do this, but I don't think it's simple enough. If my child widgets are indeterminate, I don't know how to create them dynamically.
Expanded(
child: Column(
children: <Widget>[
Expanded(
flex: 1,
child: Row(children: <Widget>[
Expanded(child: Text("1"),),
Expanded(child: Text("1"),),
],)
),
Expanded(
flex: 1,
child:Row(children: <Widget>[
Expanded(child: Text("1"),),
Expanded(child: Text("1"),),
],),
),
Expanded(
flex: 1,
child: Row(children: <Widget>[
Expanded(child: Text("1"),),
Expanded(child: Text("1"),),
],),
)
],
),
)

Answer 1

I've come up with a way to deal with this requirement by calculating the width and height of each child widget and then placing them in wrap to arrange themselves
class RowFixedWrap extends StatefulWidget {
final double spacing;
final double runSpacing;
final int columnCount;
final List<Widget> childern;
RowFixedWrap(
{Key key, this.spacing, this.runSpacing, this.columnCount, this.childern})
: super(key: key);
#override
State<StatefulWidget> createState() {
return _FixedWrapState();
}
}
class _FixedWrapState extends State<RowFixedWrap> {
#override
Widget build(BuildContext context) {
return LayoutBuilder(
builder: (context, constraints) {
var itemWidth =
(constraints.maxWidth - widget.spacing * (widget.columnCount - 1)) /
widget.columnCount;
var rows = widget.childern.length % widget.columnCount != 0
? (widget.childern.length ~/ widget.columnCount) + 1
: (widget.childern.length ~/ widget.columnCount);
var itemHeight =
(constraints.maxHeight - widget.runSpacing * (rows - 1)) / rows;
return Wrap(
spacing: widget.spacing,
runSpacing: widget.runSpacing,
children: widget.childern.map((widget) {
return SizedBox(
width: itemWidth,
height: itemHeight,
child: widget,
);
}).toList());
},
);
}
}
Expanded(
child: Padding(
padding: const EdgeInsets.all(10.0),
child: RowFixedWrap(
spacing: 10,
runSpacing: 10,
columnCount: 2,
childern: <Widget>[
Container(
color: Colors.red,
),
Container(
color: Colors.red,
),
Container(
color: Colors.red,
),
Container(
color: Colors.red,
),
],
),
));