Flutter(二十四)——参数回传

import 'package:flutter/material.dart';
class HomePage extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("主页面"),
      ),
      body: Center(
        child: JumpButton()
      ),
    );
  }
}
class JumpButton extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    return RaisedButton(
      onPressed: (){
        _showCityResult(context);
      },
      child: Text("选择城市：",style: TextStyle(fontSize: 33,color: Colors.red),),
    );
  }
  /***
   * 跳转页面并返回数据显示
   */
  _showCityResult(BuildContext context) async{
    final result=await Navigator.push(context, MaterialPageRoute(builder: (context)=>CityPage()));//跳转界面获取返回数据
    Scaffold.of(context)..removeCurrentSnackBar()..showSnackBar(SnackBar(content: Text("$result"),));//显示返回数据
  }
}

class CityPage extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("选择城市"),),
      body: Column(
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.all(10),
            child: RaisedButton(
              child: Text("武汉加油"),
              onPressed: (){
                Navigator.pop(context,"武汉加油");
              },
            ),
          ),
          Padding(
            padding: const EdgeInsets.all(10),
            child: RaisedButton(
              child: Text("湖北加油"),
              onPressed: (){
                Navigator.pop(context,"湖北加油");
              },
            ),
          ),
          Padding(
            padding: const EdgeInsets.all(10),
            child: RaisedButton(
              child: Text("中国加油"),
              onPressed: (){
                Navigator.pop(context,"中国加油");
              },
            ),
          ),
        ],
      ),
    );
  }
}