【Flutter】Android 与 Flutter 之间的代码调用

2023-12-27 21:37:36

参考资料

https://docs.flutter.dev/platform-integration/platform-channels?tab=type-mappings-java-tab

关键类

  • MethodChannel

前置条件

安装Flutter 环境,有开发工具,新建了FlutterDemo
使用AndroidStudio(2023.1.1)的FlutterDemo即可。

代码

只试验了Android平台 其他平台调用方式大差不差 API名字是一样的

Flutter代码

import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutterdemo/LogUtil.dart';
import 'package:logger/logger.dart';
import 'package:provider/provider.dart';
var _tag = "SSS";
void main() {
  runApp(const MyApp());
  logE(_tag, "1111");
  logD(_tag, "222");
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // TRY THIS: Try running your application with "flutter run". You'll see
        // the application has a purple toolbar. Then, without quitting the app,
        // try changing the seedColor in the colorScheme below to Colors.green
        // and then invoke "hot reload" (save your changes or press the "hot
        // reload" button in a Flutter-supported IDE, or press "r" if you used
        // the command line to start the app).
        //
        // Notice that the counter didn't reset back to zero; the application
        // state is not lost during the reload. To reset the state, use hot
        // restart instead.
        //
        // This works for code too, not just values: Most code changes can be
        // tested with just a hot reload.
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(),
    );
  }
}


class MyAppState extends ChangeNotifier{

}


class MyHomePage extends StatefulWidget {




  const MyHomePage({super.key});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".



  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  static const platform = MethodChannel("PlatformReceive");
  static const receiveChannel = MethodChannel("FlutterReceive");
  int _counter = 0;
  var current = WordPair.random();
  void getNext(){
    current = WordPair.random();
  }
  @override
  void initState() {
    receiveChannel.setMethodCallHandler((call) async{
      logD(_tag,"ReceiveMethod ${call.method} ${call.arguments}");
      if(call.method == "changeCount"){
        setState(() {
          _counter = call.arguments;
        });
      }
    });
    super.initState();
  }
  dynamic _incrementCounter() {
    var log = Logger();
    log.d("Float Pressed");
    platform.invokeMethod("getContent");
    setState(() {
      _counter++;
      getNext();
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
    });

  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.


    return Scaffold(
      appBar: AppBar(
        // TRY THIS: Try changing the color here to a specific color (to
        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
        // change color while the other colors stay the same.
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: ListView(children: [
          Padding(padding: EdgeInsets.all(100.0)),
          Column(
                    // Column is also a layout widget. It takes a list of children and
                    // arranges them vertically. By default, it sizes itself to fit its
                    // children horizontally, and tries to be as tall as its parent.
                    //
                    // Column has various properties to control how it sizes itself and
                    // how it positions its children. Here we use mainAxisAlignment to
                    // center the children vertically; the main axis here is the vertical
                    // axis because Columns are vertical (the cross axis would be
                    // horizontal).
                    //
                    // TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
                    // action in the IDE, or press "p" in the console), to see the
                    // wireframe for each widget.
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      const Text(
                        'You have pushed the button this many times:',
                      ),
                      Text(
                        '$_counter',
                        style: Theme.of(context).textTheme.headlineMedium,
                      ),
                      Text(current.asLowerCase),
                      Container(width: 300,height: 200,margin: EdgeInsets.all(10),child: Image.asset('assets/images/1122.jpg'),),
                      Card(color: Colors.teal,child: Padding(padding: EdgeInsets.all(40),child: Text("My name is Card King"),))
                    ],
                  ),
          Padding(padding: EdgeInsets.all(400.0)),
        ],)

      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

核心代码在_MyHomePageState 类中:

  static const platform = MethodChannel("PlatformReceive");
  static const receiveChannel = MethodChannel("FlutterReceive");
  int _counter = 0;
  var current = WordPair.random();
  void getNext(){
    current = WordPair.random();
  }
  @override
  void initState() {
    receiveChannel.setMethodCallHandler((call) async{
      logD(_tag,"ReceiveMethod ${call.method} ${call.arguments}");
      if(call.method == "changeCount"){
        setState(() {
          _counter = call.arguments;
        });
      }
    });
    super.initState();
  }
  dynamic _incrementCounter() {
    var log = Logger();
    log.d("Float Pressed");
    platform.invokeMethod("getContent");
    setState(() {
      _counter++;
      getNext();
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
    });

Android平台代码:

  static const platform = MethodChannel("PlatformReceive");
  static const receiveChannel = MethodChannel("FlutterReceive");
  int _counter = 0;
  var current = WordPair.random();
  void getNext(){
    current = WordPair.random();
  }
  @override
  void initState() {
    receiveChannel.setMethodCallHandler((call) async{
      logD(_tag,"ReceiveMethod ${call.method} ${call.arguments}");
      if(call.method == "changeCount"){
        setState(() {
          _counter = call.arguments;
        });
      }
    });
    super.initState();
  }
  dynamic _incrementCounter() {
    var log = Logger();
    log.d("Float Pressed");
    platform.invokeMethod("getContent");
    setState(() {
      _counter++;
      getNext();
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
    });

说明

  • 双方注册的MethodChannel,Channelname需要保持一致。
  • call.method 需双方保持一致。
  • call.arguments 传递什么类型就为什么类型。类型不匹配会报错。
  • 类型匹配规则如下:
    在这里插入图片描述

在这里插入图片描述

End

贴出当前电脑的flutter版本:
在这里插入图片描述
Demo地址:https://github.com/yudehai0204/FlutterStudyDemo

文章来源:https://blog.csdn.net/a940659387/article/details/135254835
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