android开发分享Flutter学习笔记（15）–App结构和导航组件

import 'package:flutter/material.dart';    void main() => runapp(myapp());    class myapp extends statefulwidget{    @override    state createstate() {      // todo: implement createstate      return new myappstate();    }    }    class myappstate extends state {    var _textcOntent= 'welcome to flutter word';    void _changetextcontent(){      setstate(() {        _textcOntent= 'what is up man???';      });    }    @override    widget build(buildcontext context) {      // todo: implement build      return new materialapp(        theme: new themedata(          primarycolor: colors.white,        ),        debugshowcheckedmodebanner: false,        title: 'demo',        home: new scaffold(          appbar: new appbar(            title: new text('demo'),            leading: icon(icons.menu,size: 30,),            actions: [              icon(icons.search,size: 30,)            ],          ),          body: new center(            child: new text(_textcontent),          ),          floatingactionbutton: new floatingactionbutton(onpressed: _changetextcontent,child: new icon(icons.adjust),),        ),      );    }  }