路由

1.通过push实现

FlatButton
    onPressed
        Navigator.of(context).push(
           MaterialPageRoute(
               builder: (BuildContext context)=>Page_About(title:'About'),
            )
        );

2. 通过router name实现

MaterialApp下定义routername

MaterialApp
   routes: {
        '/about':(context)=>Page_About(title:'about')
   },

调用处使用

onPressed: (){
   Navigator.pushNamed(context, '/about');
},

3. 根路由

MaterialApp中的home替换为initialRoute

MaterialApp
  initialRoute: '/',
  routes: {
    '/':(context)=>RouterDemo(),
  }