How to send string data from Activity to started Service onclick method?

I have one activity and service. I have three button on app. One of is Start to start Service the other is Test to send Service "Test" string the other is Stop to stop service.

I can start and stop service without any problem but when i try to send string i tried Intent but cannot find any way for this. I also tried onStartCommand() but cannot fire that method too..

What you can suggest?

Here my Activity

 override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
    serviceIntent = Intent(applicationContext, MyService::class.java)
}



fun sendLogin(view: View){
    startService(serviceIntent)
    if (isMyServiceRunning(MyService::class.java)){
        Toast.makeText(applicationContext, "Service Started", Toast.LENGTH_SHORT).show()
    }

}

fun sendTest(view: View){ //TRY TO SEND "TEST" 
    val intent = Intent(this, MyService::class.java)
    val msj = "TEST"
    intent.putExtra("key", msj)
    applicationContext.startService(intent);
}

fun sendLogout(view: View){ //Stop service
    stopService(serviceIntent)
    if (!isMyServiceRunning(MyService::class.java)){
        Toast.makeText(applicationContext, "Service Stopped", Toast.LENGTH_SHORT).show()
    }

}

private fun isMyServiceRunning(serviceClass: Class<*>): Boolean { //Checking app is started or not
    val manager = getSystemService(ACTIVITY_SERVICE) as ActivityManager
    for (service in manager.getRunningServices(Int.MAX_VALUE)) {
        if (serviceClass.name == service.service.className) {
            return true
        }
    }
    return false
}

Here my service

private inner class MessageRequestHandler() : Handler()   {
    override fun handleMessage(msg: Message) {
        when (msg.what) {
            SEND_MESSAGE_FLAG -> {
                val bundle = Bundle()
                bundle.putString("key", stringMessage)
                val mesg = Message.obtain(null, SEND_MESSAGE_FLAG)
                mesg.obj = bundle
                try {
                    msg.replyTo.send(mesg)
                } catch (e: RemoteException) {
                    Log.i(TAG, "Error: " + e.message)
                }
            }
        }

        super.handleMessage(msg)
    }

}

override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int { //Cannot fire this...
    stringMessage = intent?.extras?.getString("key").toString()
    return super.onStartCommand(intent, flags, startId)
}

private val messageMessenger: Messenger = Messenger(MessageRequestHandler())
override fun onBind(intent: Intent?): IBinder {
    return messageMessenger.binder
}

Thanks

Please check, message passing is easy using EventBus. Here's your solution:

//Define Event Class
class MessageEvent(val someString: String)

Main Activity

class MainActivity : AppCompatActivity() {
private lateinit var serviceIntent: Intent
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
serviceIntent = Intent(applicationContext, MessageService::class.java)
}
fun sendLogin(view: View){
startService(serviceIntent)
if (isMyServiceRunning(MessageService::class.java)){
Toast.makeText(applicationContext, "Service Started", Toast.LENGTH_SHORT).show()
}
}
fun sendTest(view: View){
//Post Events
EventBus.getDefault().post(MessageEvent("TEST"))
}
fun sendLogout(view: View){
stopService(serviceIntent)
if (!isMyServiceRunning(MessageService::class.java)){
Toast.makeText(applicationContext, "Service Stopped", Toast.LENGTH_SHORT).show()
}
}
private fun isMyServiceRunning(serviceClass: Class<*>): Boolean {
val manager = getSystemService(ACTIVITY_SERVICE) as ActivityManager
for (service in manager.getRunningServices(Int.MAX_VALUE)) {
if (serviceClass.name == service.service.className) {
return true
}
}
return false
}
}

And Service class

class MessageService : Service() {
private val TAG: String? = "InService"
private inner class MessageRequestHandler() : Handler()   {
override fun handleMessage(msg: Message) {
super.handleMessage(msg)
}
}
@Subscribe(threadMode = ThreadMode.MAIN)
fun onMessageEvent(event: MessageEvent?) {
Log.i(TAG, "onMessageEvent: " + event?.someString)
}
override fun onStart(intent: Intent?, startId: Int) {
super.onStart(intent, startId)
//subscribe to EventBus
EventBus.getDefault().register(this);
}
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
return super.onStartCommand(intent, flags, startId)
}
private val messageMessenger: Messenger = Messenger(MessageRequestHandler())
override fun onBind(intent: Intent?): IBinder {
return messageMessenger.binder
}
override fun onDestroy() {
super.onDestroy()
//Unsubscribe to EventBus
EventBus.getDefault().unregister(this);
}
}