Flutter 局部路由实现详解

import 'package:flutter/material.dart';

class navigatorpage extends statefulwidget {
 @override
 _navigatorpagestate createstate() => _navigatorpagestate();
}

class _navigatorpagestate extends state<navigatorpage> {
 @override
 widget build(buildcontext context) {
  return scaffold(
   appbar: appbar(
    title: text('navigator'),
   ),
   body: column(
    children: <widget>[
     text('navigator的高度为infinity'),
     text('如果直接父级非最上级也是infinity会产生异常'),
     container(
      height: 333,
      color: colors.amber.withalpha(111),
      child: navigator( // navigator
       initialroute: '/abc',
       ongenerateroute: (val) {
        routepagebuilder builder;
        switch (val.name) {
         case '/abc':
          builder = (buildcontext ncontext, animation<double> animation, animation<double> secondaryanimation) => column(
           // 并没有在 materialapp 中设定 /efg 路由
           // 因为navigator的特性 使用ncontext 可以跳转 /efg
           children: <widget>[
            text('呵呵呵'),
            raisedbutton(
             child: text('去 /efg'),
             onpressed: () {
              navigator.pushnamed(ncontext, '/efg');
             },
            )
           ],
          );
         break;
         case '/efg':
          builder = (buildcontext ncontext, animation<double> animation, animation<double> secondaryanimation) => row(
           children: <widget>[
            raisedbutton(
             child: text('去 /hhh'),
             onpressed: () {
              navigator.pushnamed(ncontext, '/hhh');
             },
            )
           ],
          );
         break;
         default:
          builder = (buildcontext ncontext, animation<double> animation, animation<double> secondaryanimation) => center(
           child: raisedbutton(
            child: text('去 /abc'),
            onpressed: () {
             navigator.pushnamed(ncontext, '/abc');
            },
           )
          );
        }
        return pageroutebuilder(
         pagebuilder: builder,
         // transitionduration: const duration(milliseconds: 0),
        );
       },
       onunknownroute: (val) {
        print(val);
       },
       observers: <navigatorobserver>[]
      ),
     ),
     text('navigator执行寻找路由顺序'),
     text('initialroute'),
     text('ongenerateroute'),
     text('onunknownroute'),
    ],
   ),
  );
 }
}