The most important thing in life is not hard work, not struggle, but choice.
Flutter side
The Flutter side creates an EventChannel channel to communicate with the native side:
var _eventChannel = EventChannel('com.flutter.guide.EventChannel');
com.flutter.guide.EventChannel is the name of EventChannel, and the native side should correspond to it.
Monitor the messages sent by the native end:
var _data;
@override
void initState() {
super.initState();
_eventChannel.receiveBroadcastStream().listen(_onData);
}
_onData(event){
setState(() {
_data = event;
});
}
Complete code on Flutter side:
class EventChannelDemo extends StatefulWidget {
@override
_EventChannelDemoState createState() => _EventChannelDemoState();
}
class _EventChannelDemoState extends State<EventChannelDemo> {
var _eventChannel = EventChannel('com.flutter.guide.EventChannel');
var _data;
@override
void initState() {
super.initState();
_eventChannel.receiveBroadcastStream().listen(_onData);
}
_onData(event){
setState(() {
_data = event;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
body: Center(
child: Text('$_data'),
),
);
}
}
Android side
Create EventChannelDemo under android :
class EventChannelDemo(var activity: Activity, messenger: BinaryMessenger):EventChannel.StreamHandler {
private var channel: EventChannel
private var index = 0
private var events: EventChannel.EventSink? = null
init {
channel = EventChannel(messenger, "com.flutter.guide.EventChannel")
channel.setStreamHandler(this)
startTimer()
}
fun startTimer() {
var timer = Timer().schedule(timerTask {
index++
var map = mapOf("name" to "dage${index}",
"age" to "${index}"
)
activity.runOnUiThread {
events?.success(map)
}
}, 0, 1000)
}
override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
this.events = events
}
override fun onCancel(arguments: Any?) {
this.events = null
}
}
The events?.success(map) method is to send data to Flutter. This method must be executed on the main thread:
activity.runOnUiThread {
events?.success(map)
}
Start in MainActivity :
class MainActivity : FlutterActivity() {
override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
super.configureFlutterEngine(flutterEngine)
EventChannelDemo(this,flutterEngine.dartExecutor.binaryMessenger)
flutterEngine.plugins.add(MyPlugin())
}
}
iOS edge
Create MethodChannelDemo under ios , as follows:
import Flutter
import UIKit
public class EventChannelDemo:NSObject, FlutterStreamHandler{
var channel:FlutterEventChannel?
var count = 0
var events:FlutterEventSink?
public override init() {
super.init()
}
convenience init(messenger: FlutterBinaryMessenger) {
self.init()
channel = FlutterEventChannel(name: "com.flutter.guide.EventChannel", binaryMessenger: messenger)
channel?.setStreamHandler(self)
startTimer()
}
func startTimer() {
let timer = Timer.scheduledTimer(timeInterval:1, target: self, selector:#selector(self.tickDown),userInfo:nil,repeats: true)
}
@objc func tickDown(){
count += 1
let args = ["count":count]
if(events != nil){
events!(args)
}
}
public func onListen(withArguments arguments: Any?, eventSink events: @escaping FlutterEventSink) -> FlutterError? {
self.events = events
return nil;
}
public func onCancel(withArguments arguments: Any?) -> FlutterError? {
self.events = nil
return nil;
}
}
Start in AppDelegate :
import UIKit
import Flutter
@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
EventChannelDemo(messenger: controller.binaryMessenger)
GeneratedPluginRegistrant.register(with: self)
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}