颤振混合布局 - 网格与行

Question

我正在尝试创建一个基本的Flutter应用程序，它有一个2乘2的文本输入网格和一个下面的按钮。

最初，我只有网格和没有按钮没有问题：

void main() => runApp(new App());
class App extends StatelessWidget {
...
  Widget build(BuildContext context) {
    return new MaterialApp(
      ...
      home: new InputWidget()
      ...
  class InputWidget extends StatefulWidget {
    Widget build(BuildContext context) {
      ... 
      _InputWidgetState createState() => new _InputWidgetState();
      ...
  class _InputWidgetState extends State<InputWidget> {
     Widget build(BuildContext context) {
       return new Scaffold(
         appBar: new AppBar(...)
         body: new Builder(
           builder: (BuildContext context) {
             return new GridView.count(
               children: <Widget>[
                 // 4 Text Fields here
               ]

我需要Scaffold内部的GridView能够使用Scaffold作为零食吧。

现在我想在这个网格下面添加一个按钮。为了达到这个目的，我在它们之间添加了几层，并且我得到了一个“溢出无穷大”的错误，其中包含以下逻辑：

void main() => runApp(new App());
class App extends StatelessWidget {
...
  Widget build(BuildContext context) {
    return new MaterialApp(
      ...
      home: new AppContainer()
      ...
  class AppContainer extends StatelessWidget {
    Widget build(BuildCOntext context) {
      return new Material( // tried Container as well
        child: new Column(
          children: <Widget>[
            new InputWidget()
            new BUttonWidget()
        ...
  class ButtonWidget extends StatelessWidget {
    Widget build(BuildContext context) {
      return new Container(
        child: new MaterialButton(...)
  ...
  class InputWidget extends StatefulWidget {
    Widget build(BuildContext context) {
      ... 
      _InputWidgetState createState() => new _InputWidgetState();
      ...
  class _InputWidgetState extends State<InputWidget> {
     Widget build(BuildContext context) {
       return new Scaffold(
         appBar: new AppBar(...)
         body: new Builder(
           builder: (BuildContext context) {
             return new GridView.count(
               children: <Widget>[
                 // 4 Text Fields here
               ]

Code＆Stack Trace。

问题似乎源于“专栏”部分。好像我需要为Column或Scaffold提供一些尺寸，但我似乎无法弄清楚我缺少哪些参数。

我在SO或Flutter文档上找不到任何可以遵循的示例 - 或者我完全错过了它。

非常感谢能够对这个布局进行排序的任何指针。

Answer 1

得到了Flutter Gitter的帮助，感谢@xqwzts和@ahmadzein。

解决方案是将每个孩子都包裹在“Expanded”中

void main() => runApp(new App());
class App extends StatelessWidget {
...
  Widget build(BuildContext context) {
    return new MaterialApp(
      ...
      home: new AppContainer()
      ...
  class AppContainer extends StatelessWidget {
    Widget build(BuildCOntext context) {
      return new Material( // tried Container as well
        child: new Column(
          children: <Widget>[
            new Expanded (
              child: new InputWidget() ... ),
            new Expanded (
              child: new Row ( 
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[new ButtonWidget()] ... )
        ...
  class ButtonWidget extends StatelessWidget {
    Widget build(BuildContext context) {
      return new Container(
        child: new MaterialButton(...)
  ...
  class InputWidget extends StatefulWidget {
    Widget build(BuildContext context) {
      ... 
      _InputWidgetState createState() => new _InputWidgetState();
      ...
  class _InputWidgetState extends State<InputWidget> {
     Widget build(BuildContext context) {
       return new Scaffold(
         appBar: new AppBar(...)
         body: new Builder(
           builder: (BuildContext context) {
             return new GridView.count(
               children: <Widget>[
                 // 4 Text Fields here
               ]