flutter 入门-字体,风格

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context){
      return MaterialApp(
        home: Scaffold(
          body: Center(
              child: Text("Hello ,geo",
              style: TextStyle(
                fontSize: 20.0 ,
                fontWeight: FontWeight.bold ,
                // letterSpacing: 2 ,
                fontFamily: 'OdibeeSans'
              ),
              ),
            ),
            floatingActionButton: FloatingActionButton(
              child : Text("button") , onPressed: (){
                print('geo') ; 
              }),
          )
      ) ;
  }
}