公司做网站的费属于广告费么,国内做网站大公司,合肥网站制作报,辽源网站建设通信原理
我们分几种场景来介绍Flutter和Native之间的通信。
Native发送数据给FlutterFlutter发送数据给NativeFlutter发送数据给Native#xff0c;然后Native回传数据给Flutter Flutter与Native通信机制
在讲解Flutter与Native之间是如何传递数据之前#xff0c;我们先了…通信原理
我们分几种场景来介绍Flutter和Native之间的通信。
Native发送数据给FlutterFlutter发送数据给NativeFlutter发送数据给Native然后Native回传数据给Flutter Flutter与Native通信机制
在讲解Flutter与Native之间是如何传递数据之前我们先了解下Flutter与Native的通信机制Flutter和Native的通信是通过Channel来完成的。
消息使用Channel(平台通道)在客户端(UI)和主机(平台)之间传递如下图所示
Channel所支持的数据类型对照表 Flutter定义了三种不同类型的Channel BasicMessageChannel用于传递字符串和半结构化的信息持续通信收到消息后可以回复此次消息如Native将遍历到的文件信息陆续传递到Flutter在比如Flutter将从服务端陆陆续续获取到信息交给Native加工Native处理完返回等MessageChannel用于传递方法调用一次性通信如Flutter调用Native拍照EventChannel用于数据流的通信持续通信通常用于Native向Flutter的通信如手机电量变化网络连接变化等
这三种类型的Channel都是全双工通信即ABFlutter可以主动发送消息给Native端并且Native接收到消息后可以做出回应同样Native端可以主动发送消息给Flutter端Flutter端接收到数据后返回给Native。
通信原理 无论是哪一种类型的Channel它能和Flutter进行通信主要是借助BinaryMessenger来实现的。三种类型的Channel在Flutter侧都有对应的实现。
实践
flutter主动发送数据给nativenative接受到消息后回信给flutter Android端
class MainActivity : FlutterActivity() {override fun configureFlutterEngine(flutterEngine: FlutterEngine) {super.configureFlutterEngine(flutterEngine)val channel MethodChannel(flutterEngine.dartExecutor.binaryMessenger, HiFlutterBridge)//HiFlutterBridge需要和flutter端的对应channel.setMethodCallHandler { call, result -Log.e(HiFlutterBridge, argus is ${call.arguments})if (call.method goToNative) {val data Hello from native!result.success(data)} else {result.notImplemented()}}}Flutter端
import package:flutter/cupertino.dart;
import package:flutter/services.dart;class HiFlutterBridge {static HiFlutterBridge _instance HiFlutterBridge._();final MethodChannel _bridge const MethodChannel(HiFlutterBridge);//需要和原生端的MethodChannel方法的第二个参数一致var _listener {};HiFlutterBridge._() {_bridge.setMethodCallHandler((MethodCall call) {String method call.method;if (_listener[method] ! null) {return _listener[method](call);}return Future(() null);});}static HiFlutterBridge getInstance() {return _instance;}register(String method, Function(MethodCall) callBack) {_listener[method] callBack;}unRegister(String method) {_listener.remove(method);}goToNative(Map params) async {String result await _bridge.invokeMethod(goToNative, params);debugPrint(HiFlutterBridge result is $result);}MethodChannel bridge() {return _bridge;}
} overrideWidget build(BuildContext context) {// TODO: implement buildreturn Scaffold(resizeToAvoidBottomInset: false, // 设置为false以避免在打开软键盘时widget被顶上去body: HideKeyboard(child: Stack(children: Widget[Align(alignment: Alignment.center,child: ElevatedButton(onPressed: () {//flutter向native端通信HiFlutterBridge.getInstance().goToNative({test: hello world})},// style: ElevatedButton.styleFrom(// minimumSize: const Size(100, 50),// maximumSize: const Size(100, 50),// shape:// RoundedRectangleBorder(borderRadius: BorderRadius.circular(30))),child: const Text(login),),)],)));}native主动发送数据给flutterflutter接受到消息后回信给native Android端
class MainActivity : FlutterActivity() {override fun onResume() {super.onResume()sendDataToFlutter()}private fun sendDataToFlutter() {val channel MethodChannel(flutterEngine!!.dartExecutor.binaryMessenger, test)channel.invokeMethod( sendData , Hello Flutter, object : MethodChannel.Result {override fun success(o: Any?) {Log.d(Native, Received back: o.toString())}override fun error(s: String, s1: String?, o: Any?) {Log.e(Native, Error: $s1)}override fun notImplemented() {}})}
}Flutter端
import package:flutter/cupertino.dart;
import package:flutter/services.dart;class HiFlutterBridge {static HiFlutterBridge _instance HiFlutterBridge._();final MethodChannel _bridge const MethodChannel(test);var _listener {};HiFlutterBridge._() {_bridge.setMethodCallHandler((MethodCall call) async{debugPrint(test ${call});return flutter native;String method call.method;if (_listener[method] ! null) {return _listener[method](call);}return Future(() null);});}static HiFlutterBridge getInstance() {return _instance;}register(String method, Function(MethodCall) callBack) {_listener[method] callBack;}unRegister(String method) {_listener.remove(method);}goToNative(Map params) async {String result await _bridge.invokeMethod(goToNative, params);debugPrint(HiFlutterBridge result is $result);}MethodChannel bridge() {return _bridge;}
} overridevoid initState() {// TODO: implement initStatesuper.initState();HiFlutterBridge.getInstance();}运行结果
I/flutter (27181): test MethodCall( sendData , Hello Flutter)
D/Native (27181): Received back: flutter native