flutter sizeBox设置具体尺寸

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
        title: "sizeBox设置具体尺寸",
        home: Scaffold(
            appBar: AppBar(
              title: Text('sizeBox设置具体尺寸'),
            ),
            body: SizedBox(
              width: 300,
              height: 300,
              child: Card(
                child: Text('邢伟新'),
              ),
            )));
  }
}