第1节：用于测试交互的Flutter项目

本节学习内容：通过Flutter的平台通道在Flutter工程中建立提供给原生项目的方法及接收从原生项目返回的值。

本节学习用时：30分钟

本节学习方式：动手实践

本节目录：

一、本节内容介绍

二、本节代码解释

一、本节内容介绍

1、主要介绍的知识点有：

• 在iOS界面中点击一个按钮跳转到Flutter页面，该Flutter页面有需要传参Main页面

2、要实现的效果如下图所示：

3、实现本节效果的代码

本节所有代码文件为：main.dart、StatelessMainPage.dart、StatefulMainPage.dart、NewRouteNoneParam.dart、NewRouteWithParam。

您可自己通过flutter create materialappproject创建materialappproject项目后，将其lib文件夹下的代码文件替换为如下即可。

3.1、其中完整的main.dart代码如下：

import 'package:flutter/material.dart';
import 'StatelessMainPage.dart';
import 'StatefulMainPage.dart';
import 'NewRouteNoneParam.dart';
import 'NewRouteWithParam.dart';



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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Platform Channel Demo',
      home: StatelessMainPage(), //不需传参数的Flutter页面
      //home: StatefulMainPage(), //需传参数的Flutter页面
      routes: {
        'StatelessMainPage':(context) => StatelessMainPage(),
        'StatefulMainPage':(context) => StatefulMainPage(),
        'NewRouteNoneParam':(context) => NewRouteNoneParam(),
        'NewRouteWithParam':(context) => NewRouteWithParam()
      }
    );
  }
}

3.2、其中完整的StatelessMainPage.dart代码如下：

import 'package:flutter/material.dart';
import 'StatefulMainPage.dart';
import 'NewRouteNoneParam.dart';
import 'NewRouteWithParam.dart';

import 'package:flutter/services.dart';
import 'dart:async';

// 已写在main.dart中
//void main() => runApp(MyApp());
//
//class MyApp extends StatelessWidget {
//  @override
//  Widget build(BuildContext context) {
//    return MaterialApp(
//      title: 'Platform Channel Demo',
//      home: StatelessMainPage(),
//      routes: {
//        'newRoute':(context) => NewRoute(),
//        'newRouteWithParam':(context) => NewRouteWithParam(),
//        'StatefulMainPage':(context) => StatefulMainPage()
//      }
//    );
//  }
//}

class StatelessMainPage extends StatelessWidget {
  // 创建一个给native的channel (类似iOS的通知）
  static const methodChannel = const MethodChannel('com.dvlproad.ciyouzen/platform_channel');

  // 给客户端发送一些东东, 这里先不用去拿回什么
  Future<Null> _showToast() async {
    try {
      await methodChannel.invokeMethod('showToast','这是我在Flutter中写的文字');
    } on PlatformException {

    }
  }

  Future<Null> _goBack() async {
    try {
      await methodChannel.invokeMethod('goBack');
    } on PlatformException {

    }
  }

  Future<Null> _goiosPage() async {
    try {
      Map<String, dynamic> map = { "content": "flutter传给iOS的内容","data":[1,2,3,4,5]};
      await methodChannel.invokeMethod('goiosPage', map);
    } on PlatformException {

    }
  }

  @override
  Widget build(BuildContext context) {
    //Scaffold是Material中主要的布局组件.
    return new Scaffold(
        appBar: new AppBar(
          leading: new IconButton(
            icon: new Icon(Icons.menu),
            tooltip: 'Navigation menu',
            onPressed: null,
          ),
          title: new Text('platform channel Example title'),
          actions: <Widget>[
//            new IconButton(
//              icon: new Icon(Icons.search),
//              tooltip: 'Search',
//              //onPressed: null,
//              onPressed: () {
//                goStatefulMainPage(context);
//              },
//            ),
            new FlatButton(
                child: Image.asset('lib/Resources/nav_right_gray_normal.png'),
                onPressed: (){
                  goStatefulMainPage(context);
                }),
          ],
        ),
        //body占屏幕的大部分
        body: new Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              new Text('Hello, platform channel!'),
              new RaisedButton(
                  child: Text('showToast'),
                  onPressed: (){
                    _showToast();
                  }
              ),
              new RaisedButton(
                  child: Text('goBack'),
                  onPressed: (){
                    _goBack();
                  }
              ),
              new RaisedButton(
                  child: Text('goiosPage'),
                  onPressed: (){
                    _goiosPage();
                  }
              ),

            ],
          ),
        ),
        floatingActionButton: new FloatingActionButton(
          tooltip: 'Add', // used by assistive technologies
          child: new Icon(Icons.add),
          onPressed: () {
             goNextPageNoneParam(context);
          },
        )
    );
  }
}

void goNextPageNoneParam(context) {
  Navigator.push(context, new MaterialPageRoute(builder: (context) {
    return new NewRouteNoneParam();
  }));
}


void goNextPageWithParams(context) {
  Navigator.push(context, new MaterialPageRoute(builder: (context) {
    return new NewRouteWithParam();
  }));
}

void goStatefulMainPage(context) {
  Navigator.push(context, new MaterialPageRoute(builder: (context) {
    return new StatefulMainPage();
  }));
}

3.3、其中完整的StatefulMainPage.dart代码如下：

import 'package:flutter/material.dart';
import 'NewRouteNoneParam.dart';

import 'package:flutter/services.dart';
import 'dart:async';


// 已写在main.dart中
//void main() => runApp(MyApp());
//
//class MyApp extends StatelessWidget {
//  @override
//  Widget build(BuildContext context) {
//    return MaterialApp(
//      title: 'Platform Channel Demo',
//
//      home: StatefulMainPage(),
//    );
//  }
//}

class StatefulMainPage extends StatefulWidget {

  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return StatefulMainPageState();
  }
}

class StatefulMainPageState extends State<StatefulMainPage> {
  // 创建一个给native的channel (类似iOS的通知）
  static const methodChannel = const MethodChannel(
      'com.dvlproad.ciyouzen/platform_channel');

  // 给客户端发送一些东东, 这里先不用去拿回什么
  Future<Null> _showToast() async {
    try {
      await methodChannel.invokeMethod('showToast','这是我在Flutter中写的文字');
    } on PlatformException {

    }
  }

  Future<Null> _goBack() async {
    try {
      await methodChannel.invokeMethod('goBack');
    } on PlatformException {

    }
  }

  Future<Null> _goiosPage() async {
    try {
      Map<String, dynamic> map = { "content": "flutter传给iOS的内容","data":[1,2,3,4,5]};
      await methodChannel.invokeMethod('goiosPage', map);
    } on PlatformException {

    }
  }

  String imageName = "lib/Resources/message_arrow.png";
  Future<Null> _changeLeftBarButtonAction() async {
    try {
      Map<String, dynamic> map = { "content": "flutter传给iOS的内容","data":[1,2,3,4,5]};
      final Map dict = await methodChannel.invokeMethod('changeLeftBarButtonAction', map);

      setState(() {
        imageName = dict["imageName"];
        print(imageName);
      });
    } on PlatformException {

    }
  }

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _changeLeftBarButtonAction();
  }

  @override
  Widget build(BuildContext context) {
    //Scaffold是Material中主要的布局组件.
    return new Scaffold(
        appBar: new AppBar(
          leading: new FlatButton(
//              child: Image.asset('lib/Resources/nav_back_white_normal.png'),
              child: Image.asset(imageName),
              onPressed: (){
                  _goBack();
              }),

//          new IconButton(
//            icon: new Icon(Icons.menu),
////          icon: Image.asset('lib/Resources/message_arrow.png'),
//            tooltip: 'Navigation menu',
//            onPressed: null,
//          ),
          title: new Text('StatefulMainPage'),
          actions: <Widget>[
//            new IconButton(
//              icon: new Icon(Icons.search),
//              tooltip: 'Search',
//              onPressed: null,
//            ),
            new FlatButton(
                child: Image.asset('lib/Resources/nav_right_gray_normal.png'),
                onPressed: null
            ),
          ],
        ),
        //body占屏幕的大部分
        body: new Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Image.asset('lib/Resources/message_arrow.png'),
              new Text('Hello, StatefulMainPage!'),
              new RaisedButton(
                  child: Text('showToast'),
                  onPressed: (){
                    _showToast();
                  }
              ),
              new RaisedButton(
                  child: Text('goBack'),
                  onPressed: (){
                    _goBack();
                  }
              ),
              new RaisedButton(
                  child: Text('goiosPage'),
                  onPressed: (){
                    _goiosPage();
                  }
              ),

            ],
          ),
        ),
        floatingActionButton: new FloatingActionButton(
          tooltip: 'Add', // used by assistive technologies
          child: new Icon(Icons.add),
          onPressed: () {
            goNextPageNoneParam(context);
          },
        )
    );
  }
}

void goNextPageNoneParam(context) {
  Navigator.push(context, new MaterialPageRoute(builder: (context) {
    return new NewRouteNoneParam();
  }));
}

3.4、其中完整的NewRouteNoneParam.dart代码如下：

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'dart:async';

class NewRouteNoneParam extends StatelessWidget {
  static const methodChannel = const MethodChannel('com.dvlproad.ciyouzen/platform_channel');
  Future<Null> _goBack() async {
    try {
      await methodChannel.invokeMethod('goBack');
    } on PlatformException {

    }
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("New route none Param"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text("This is new route"),
            RaisedButton(
              child: Text('goback'),
              onPressed: _goBack
            )
          ],
        )

      ),
    );
  }
}

3.5、其中完整的NewRouteWithParam.dart代码如下：

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'dart:async';

class NewRouteWithParam extends StatelessWidget {
  static const methodChannel = const MethodChannel('com.dvlproad.ciyouzen/platform_channel');
  Future<Null> _goBack() async {
    try {
      await methodChannel.invokeMethod('goBack');
    } on PlatformException {

    }
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("New route with params"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text("This is new route with params"),
            RaisedButton(
              child: Text('goback'),
              onPressed: _goBack
            )
          ],
        )

      ),
    );
  }
}