Flutter:如何在ModalBottomSheet中减小CupertinoPicker的大小？

Question

每当我试图在ModalBottomSheet、Column、Row或Container中设置一个CupertinoPicker时，它似乎占据了最大可能的位置。

有没有办法将ModalBottomSheet的大小/高度限制为CupertinoPicker的实际大小，这显然比ModalBottomSheet的高度小得多(通过其灰色背景颜色变得明显)。

下面是我的代码：

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}


class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(body:
    Center(child: RaisedButton(onPressed: () => showPicker(context),
        child: Text('Show Bottom Sheet')),)
    );
  }


  Widget showPicker(BuildContext context) {
    showModalBottomSheet(
        context: context,
        builder: (context) {
              return Container(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: <Widget>[
                    Text('This is a picker'),
                    Expanded(
                      child: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: <Widget>[
                          Expanded(
                            child: Container(
                              height: 100,
                              child: CupertinoPicker(
                                itemExtent: 30,
                                onSelectedItemChanged: (int index) {
                                  print(index);
                                },
                                children: <Widget>[
                                  Center(child: Text("Item 1")),
                                  Center(child: Text("Item 2")),
                                  Center(child: Text("Item 3")),
                                ],
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
              );

        });
  }

}

这是我得到的：

​

​

感谢您的任何提示，提示和建议！

Answer 1

  Widget showPicker(BuildContext context) {
    showModalBottomSheet(
        context: context,
        builder: (context) {
              return Container(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: <Widget>[
                    Text('This is a picker'),
                    Row(
                      mainAxisSize: MainAxisSize.min,
                      children: <Widget>[
                        Expanded(
                          child: Container(
                            height: 100,
                            child: CupertinoPicker(
                              itemExtent: 30,
                              onSelectedItemChanged: (int index) {
                                print(index);
                              },
                              children: <Widget>[
                                Center(child: Text("Item 1")),
                                Center(child: Text("Item 2")),
                                Center(child: Text("Item 3")),
                              ],
                            ),
                          ),
                        ),
                      ],
                    ),
                  ],
                ),
              );

        });
  }

这样可以解决粘贴问题的方法，你会得到你想要的输出