如何将代码分配给参数

选项1当然有效

children: <Widget>[
 MyContainer('1', 75.0, 75.0, 0.0),
 MyContainer('2', 75.0, 75.0, 0.0),
 MyContainer('3', 75.0, 75.0, 0.0),
 MyContainer('4', 75.0, 75.0, 0.0),
 MyContainer('5', 75.0, 75.0, 0.0),
],

2 选项工作

children: f1(),

List f1() {
 var ara = List<Widget>();
 for(int i=0; i<5;) {
  i++;
  ara.add(MyContainer(i.toString(), 75.0, 75.0, 0.0));
 }
 return ara;
}

当然，选项 3不起作用。如何在选项 3 中插入​​代码，是否可能？谢谢你。

children:
 for(int i=0; i<5;) {
  i++;
  MyContainer(i.toString(), 75.0, 75.0, 0.0);
 },

完整的代码示例

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
 @override
 Widget build(BuildContext context) {
  return MaterialApp(
   debugShowCheckedModeBanner: false,
   title: 'Name App',
   theme: ThemeData(
    primarySwatch: Colors.blue,
   ),
   home: Scaffold(
    appBar: AppBar(
     //title: Text('Name Page'),
    ),
    body: MyHomePage(),
   ),
  );
 }
}

class MyHomePage extends StatelessWidget {
 @override
 Widget build(BuildContext context) {
  return Container(
   width: double.infinity,
   height: null,
   color: Colors.amber,
   child: Wrap(
    direction: Axis.horizontal,
    spacing: 10.0,
    runSpacing: 10.0,
    //1 ВАРИАНТ
    /*children: <Widget>[
     MyContainer('1', 75.0, 75.0, 0.0),
     MyContainer('2', 75.0, 75.0, 0.0),
     MyContainer('3', 75.0, 75.0, 0.0),
     MyContainer('4', 75.0, 75.0, 0.0),
     MyContainer('5', 75.0, 75.0, 0.0),
    ],*/

    children: f1(), //2 ВАРИАНТ

    //3 ВАРИАНТ не работает
    /*children:
     for(int i=0; i<5;) {
      i++;
      ara.add(MyContainer(i.toString(), 75.0, 75.0, 0.0));
     },*/
   ),
  );
 }
}

class MyContainer extends StatelessWidget {
 final String _str;
 final double _width;
 final double _height;
 final double _margin;

 MyContainer(this._str, this._width, this._height, this._margin);

 @override
 Widget build(BuildContext context) {
   return Container(
    width: _width,
    height: _height,
    margin: EdgeInsets.all(_margin),
    color: Colors.pink,
    alignment: Alignment.center,
    child: Text(
     _str,
     style: TextStyle(
      color: Colors.white,
      fontSize: 22.0,
     ),
    ),
   );
 }
}

List f1() {
 var ara = List<Widget>();
 for(int i=0; i<5;) {
  i++;
  ara.add(MyContainer(i.toString(), 75.0, 75.0, 0.0));
 }
 return ara;
}