Android Service功能使用示例代码

import android.app.Service
import android.content.Intent
import android.os.IBinder
import android.util.Log
class MyService : Service() {
    private val TAG = "MyService"
    override fun onBind(intent: Intent?): IBinder? {
        // 这个方法只有在绑定服务时才会调用
        return null
    }
    override fun onCreate() {
        super.onCreate()
        Log.d(TAG, "Service Created")
    }
    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
        Log.d(TAG, "Service Started")
        // 在这里执行后台任务
        return START_STICKY
    }
    override fun onDestroy() {
        super.onDestroy()
        Log.d(TAG, "Service Destroyed")
    }
}

<service android:name=".MyService" />

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val startButton: Button = findViewById(R.id.startButton)
        val stopButton: Button = findViewById(R.id.stopButton)
        startButton.setOnClickListener {
            val intent = Intent(this, MyService::class.java)
            startService(intent)
        }
        stopButton.setOnClickListener {
            val intent = Intent(this, MyService::class.java)
            stopService(intent)
        }
    }
}

import android.app.Service
import android.content.Intent
import android.os.Binder
import android.os.IBinder
class MyBoundService : Service() {
    private val binder = LocalBinder()
    inner class LocalBinder : Binder() {
        fun getService(): MyBoundService = this@MyBoundService
    }
    override fun onBind(intent: Intent?): IBinder? {
        return binder
    }
    fun performAction() {
        // 执行某个操作
    }
}

import android.content.ComponentName
import android.content.Context
import android.content.Intent
import android.content.ServiceConnection
import android.os.Bundle
import android.os.IBinder
import androidx.appcompat.app.AppCompatActivity
import android.widget.Button
class MainActivity : AppCompatActivity() {
    private var myService: MyBoundService? = null
    private var isBound = false
    private val connection = object : ServiceConnection {
        override fun onServiceConnected(className: ComponentName, service: IBinder) {
            val binder = service as MyBoundService.LocalBinder
            myService = binder.getService()
            isBound = true
        }
        override fun onServiceDisconnected(arg0: ComponentName) {
            isBound = false
        }
    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val bindButton: Button = findViewById(R.id.bindButton)
        val unbindButton: Button = findViewById(R.id.unbindButton)
        val actionButton: Button = findViewById(R.id.actionButton)
        bindButton.setOnClickListener {
            Intent(this, MyBoundService::class.java).also { intent ->
                bindService(intent, connection, Context.BIND_AUTO_CREATE)
            }
        }
        unbindButton.setOnClickListener {
            if (isBound) {
                unbindService(connection)
                isBound = false
            }
        }
        actionButton.setOnClickListener {
            if (isBound) {
                myService?.performAction()
            }
        }
    }
}