xamarin - Flutter 中的 Xamarin MessagingCenter 相当于什么？

Question

与 Xamarin , 我们一般用Message-Center在应用程序运行时向任何页面发送消息(启动应用程序或应用程序是后台)。

与 Flutter ，我们有什么方法可以发送与 Message-Center 相同的消息吗？的 Xamarin.Forms ?

Answer 1

根据我的研究，您可以使用 Channel实现这一目标。

BasicMessageChannel是一个类似的 channel 。

原生部分 .

    private final Activity activity;
    private final BasicMessageChannel<String> messageChannel;

    static BasicMessageChannelPlugin registerWith(FlutterView flutterView) {
        return new BasicMessageChannelPlugin(flutterView);
    }

    private BasicMessageChannelPlugin(FlutterView flutterView) {
        this.activity = (Activity) flutterView.getContext();
        this.messageChannel = new BasicMessageChannel<>(flutterView, "BasicMessageChannelPlugin", StringCodec.INSTANCE);
        //Set up a message handler to handle messages from Dart
        messageChannel.setMessageHandler(this);
    }

    @Override
    public void onMessage(String s, BasicMessageChannel.Reply<String> reply) {//Handle messages from Dart
        reply.reply("BasicMessageChannel：" + s);//Can reply by `reply`
        if (activity instanceof IShowMessage) {
            ((IShowMessage) activity).onShowMessage(s);
        }
        Toast.makeText(activity, s, Toast.LENGTH_SHORT).show();
    }

    /**
     * Send Dart a message and receive feedback from Dart
     *
     * @param message  Content of the message to send to Dart
     * @param callback Feedback from Dart
     */
    void send(String message, BasicMessageChannel.Reply<String> callback) {
        messageChannel.send(message, callback);
    }

    @Override
    public void reply(String s) {

    }
}

Dart 部分

import 'package:flutter/services.dart';
static const BasicMessageChannel _basicMessageChannel =
const BasicMessageChannel('BasicMessageChannelPlugin', StringCodec());

//Use BasicMessageChannel to receive messages from Native and reply to Native
_basicMessageChannel
    .setMessageHandler((String message) => Future<String>(() {
          setState(() {
            showMessage = message;
          });
          return "receive Native's message：" + message;
        }));
//use BasicMessageChannelsend message to Native And accept Native's reply
String response;
    try {
       response = await _basicMessageChannel.send(value);
    } on PlatformException catch (e) {
      print(e);
    }

这是关于它的博客。
https://stablekernel.com/flutter-platform-channels-quick-start/