使用flutter控制蓝牙通讯_Android与flutter 的消息通讯
Flutter 与 Android iOS 原生的通信有以下三种方式
BasicMessageChannel：
用于传递字符串和半结构化的信息，Flutter和平台端进行消息数据交换时候可以使用。
MethodChannel：
用于传递方法调用(method invocation)，Flutter和平台端进行直接方法调用时候可以使用。
EventChannel：
用于数据流(event streams)的通信，Flutter和平台端进行事件监听、取消等可以使用。
以下以BasicMessageChannel为例，介绍以下用法：
先创建一个工具类
public class PlatformUtil {
private static String Default_Message_Key = "key_platform_default";
public PlatformUtil(BinaryMessenger binaryMessenger) {
this.binaryMessenger = binaryMessenger;
}
private BasicMessageChannel messageChannel;
private MethodChannel methodChannel;
private EventChannel eventChannel;
private BinaryMessenger binaryMessenger;
public BasicMessageChannel createBasicMessageChannel(String key) {
if (messageChannel == null)
messageChannel = new BasicMessageChannel<>(binaryMessenger, key, StandardMessageCodec.INSTANCE);
return messageChannel;
}
public BasicMessageChannel createBasicMessageChannel() {
return createBasicMessageChannel(Default_Message_Key);
}
public MethodChannel createMethodChannel(String key) {
if (methodChannel == null)
methodChannel = new MethodChannel(binaryMessenger, key, StandardMethodCodec.INSTANCE);
return methodChannel;
}
public MethodChannel createMethodChannel() {
return createMethodChannel(Default_Message_Key);
}
public EventChannel createEventChannel(String key) {
if (eventChannel == null)
eventChannel = new EventChannel(binaryMessenger, key, StandardMethodCodec.INSTANCE);
return eventChannel;
}
public EventChannel createEventChannel() {
return createEventChannel(Default_Message_Key);
}
}
创建一个FlutterActicity
public class TestAty extends FlutterActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addFlutterView();
requestData();
}
private PlatformUtil platformUtil;
private void addFlutterView(){
FlutterView flutterView = Flutter.createView(this,getLifecycle(),"test1");
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT);
platformUtil = new PlatformUtil(flutterView);
addContentView(flutterView,layoutParams);
}
protected void requestData() {
//test send msg
JSONObject object = new JSONObject();
try {
object.put("code","200");
object.put("message","send");
object.put("data","i want to send message to you");
}catch (Exception e){
e.toString();
}
platformUtil.createBasicMessageChannel().send(object.toString(), new BasicMessageChannel.Reply() {
@Override
public void reply(@Nullable Object reply) {
L.e("receive--"+reply.toString());
}
});
platformUtil.createBasicMessageChannel().setMessageHandler(new BasicMessageChannel.MessageHandler() {
@Override
public void onMessage(@Nullable Object message, @NonNull BasicMessageChannel.Reply reply) {
L.e("receive--"+message.toString());
try {
object.put("code","200");
object.put("message","receive");
object.put("data","i know");
}catch (Exception e){
e.toString();
}
reply.reply(object.toString());
}
});
//test call method
//test register event
}
}
创建一个dart工具类
import 'package:flutter/services.dart';
import 'dart:convert';
const String default_key_code = "key_platform_default";
var messageChannel = const BasicMessageChannel(default_key_code, StandardMessageCodec());
void sendMessage() async{
Map sourceMap = new Map();
sourceMap.putIfAbsent("code", ()=>("200"));
sourceMap.putIfAbsent("message", ()=>("test"));
sourceMap.putIfAbsent("data", ()=>("testData"));
String jsonString = jsonEncode(sourceMap);
print(jsonString);
try{
String reply = await messageChannel.send(jsonString);
print("dart:receive--"+reply.toString());
}on PlatformException catch(e){
print(e);
}
}
void receiveMessage(){
messageChannel.setMessageHandler((message) async{
print("dart:receive--+$message");
TestMode testMode = new TestMode("200", "receive", "222");
return jsonEncode(testMode.toJson());
});
}
class TestMode{
String code;
String message;
String data;
TestMode(this.code, this.message, this.data);
TestMode.fromJson(Map json){
code = json['code'];
message = json['message'];
data = json['data'];
}
Map toJson() {
final Map data = new Map();
data['code'] = this.code;
data['message'] = this.message;
data['data'] = this.data;
return data;
}
}
创建一个dart widget
import 'package:flutter/material.dart';
import 'platform_util.dart';
class MyTestApp extends StatelessWidget{
@override
Widget build(BuildContext context) {
receiveMessage();
sendMessage();
return new MaterialApp(
title: 'welcome use flutter',
home: new Scaffold(
appBar: new AppBar(
title: new Text('welcome title'),
),
body: new Center(
child: new Text('welcome body'),
),
),
);
}
}
运行得到如下结果：
2020-02-06 10:43:15.808 14590-14929/com.aa.bb I/flutter: dart:receive--+{"code":"200","message":"send","data":"i want to send message to you"}
2020-02-06 10:43:15.813 14590-14929/com.aa.bb I/flutter: {"code":"200","message":"test","data":"testData"}
2020-02-06 10:43:15.827 14590-14590/com.aa.bb E/=====Leen=====: receive--{"code":"200","message":"test","data":"testData"}
2020-02-06 10:43:16.247 14590-14590/com.aa.bb E/=====Leen=====: receive--{"code":"200","message":"receive","data":"222"}
2020-02-06 10:43:16.418 14590-14929/com.aa.bb I/flutter: dart:receive--{"code":"200","message":"receive","data":"i know"}