我的應用程式模塊啟動作為前臺服務運行的位置跟蹤器/提示器。我作業得很好，但 Android Studio 給了我這個警告：
private lateinit var locationActivity: Activity
=> Do not place Android context classes in static fields; this is a memory leak
下面是模塊代碼：
package com.DevID.AppID
import android.Manifest
import android.app.*
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.location.Location
import android.net.Uri
import android.os.Build
import android.os.IBinder
import android.os.Looper
import androidx.core.app.NotificationCompat
import androidx.core.content.ContextCompat
import com.android.volley.Request
import com.android.volley.RequestQueue
import com.android.volley.toolbox.StringRequest
import com.android.volley.toolbox.Volley
import com.google.android.gms.location.*
import java.util.*
import kotlin.concurrent.fixedRateTimer
private var createCount = 0
private var initialized = false
private var LocationServiceRunning = false
private var locationService: LocationService = LocationService()
private lateinit var locationIntent: Intent
private lateinit var locationCallback: LocationCallback
private lateinit var VolleyQueue: RequestQueue
private lateinit var locationActivity: Activity // **WARNING: Do not place Android context classes in static fields; this is a memory leak**
fun startLocationService(activity: Activity, enable: Boolean) {
LocationService.Enabled = enable
locationIntent = Intent(activity, locationService.javaClass)
VolleyQueue = Volley.newRequestQueue(activity)
locationActivity = activity
if (LocationService.Enabled) {
if (!LocationServiceRunning) {
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
reportEvent("NOPERMIS")
val errorNotif = createNotification(
activity,
"Error: location not available",
"Click to open settings and allow location access",
NotificationCompat.PRIORITY_MAX,
Notification.CATEGORY_ERROR,
Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.fromParts("package", activity.packageName, null))
)
(activity.getSystemService(Service.NOTIFICATION_SERVICE) as NotificationManager).notify(99, errorNotif)
} else {
reportEvent("STARTING")
createCount = 0
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { // Oreo = Android 8.0 = API level 26
activity.startForegroundService(locationIntent)
} else {
activity.startService(locationIntent)
}
}
}
} else {
if (LocationServiceRunning) {
reportEvent("STOPPING")
activity.stopService(locationIntent)
} else {
(activity.getSystemService(Service.NOTIFICATION_SERVICE) as NotificationManager).cancel(99) // Clean up any error notifications
}
}
}
fun reportEvent(event: String) {
VolleyQueue.add(StringRequest(Request.Method.GET, "${LocationService.ReportURL}&report=$event", {}, {}))
}
fun createNotification(activity: Activity, title: String, text: String, priority: Int, category: String?, intent: Intent): Notification {
val channelID = "LOCATION_SERVICE"
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
val channelName = "Location Service"
val chan = NotificationChannel(channelID, channelName, NotificationManager.IMPORTANCE_LOW)
chan.lockscreenVisibility = Notification.VISIBILITY_PUBLIC
val manager = activity.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
manager.createNotificationChannel(chan)
}
return NotificationCompat.Builder(activity, channelID)
.setOngoing(true)
.setSmallIcon(R.drawable.ic_stat_ic_notification)
.setContentTitle(title)
.setContentText(if (text == "") null else text)
.setPriority(priority)
.setCategory(category)
.setContentIntent(
TaskStackBuilder.create(activity)
.addNextIntent(intent)
.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT)
)
.setShowWhen(true)
.setWhen(System.currentTimeMillis())
.build()
}
class LocationService : Service() {
companion object {
var ReportURL: String = ""
var ReportInterval: Long = 60000 // 60 Seconds
var ReportTitle: String = "App is running"
var ReportText: String = ""
var Enabled: Boolean = false
}
private val startTime = now()
private var locGPS: String = ""
private var locCount = 0
private var locTime = startTime
private lateinit var locationTimer: Timer
private fun now(): Int {
return (System.currentTimeMillis() / 1000).toInt()
}
override fun onCreate() {
super.onCreate()
LocationServiceRunning = true
createCount
if (Enabled) {
showNotification()
startLocationUpdates()
}
}
private fun showNotification() {
val locNotif = createNotification(
locationActivity,
ReportTitle,
ReportText,
NotificationCompat.PRIORITY_MIN,
Notification.CATEGORY_SERVICE,
Intent(this, MainActivity::class.java)
)
startForeground(99, locNotif)
}
private fun startLocationUpdates() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return
}
locationTimer = fixedRateTimer("timer", false, 5000, ReportInterval * 1000) {
val start = now() - startTime
val last = now() - locTime
VolleyQueue.add(StringRequest( // https://developer.android.com/training/volley/simple
Request.Method.GET,
"${ReportURL}&gps=$locGPS&count=$locCount&start=$start&last=$last&wait=${ReportInterval}&agent=App",
{ response ->
val lines = response.lines()
lines.forEach { line ->
when {
line == "start" -> startLocationService(applicationContext as MainActivity, true)
line == "stop" -> startLocationService(applicationContext as MainActivity, false)
line.startsWith("text:") -> ReportText = line.substring(5)
line.startsWith("title:") -> ReportTitle = line.substring(6)
line == "show" -> showNotification()
else -> Log.w("?_LocationService", "bad response line: $line")
}
}
},
{
ReportTitle = "Error: connection lost"
ReportText = ""
showNotification()
}
))
}
val request = LocationRequest.create().apply {
interval = ReportInterval
fastestInterval = 20000
priority = LocationRequest.PRIORITY_HIGH_ACCURACY
}
locationCallback = object : LocationCallback() {
override fun onLocationResult(locationResult: LocationResult) {
val location: Location = locationResult.lastLocation
locGPS = location.latitude.toString() "," location.longitude.toString()
locCount
locTime = now()
}
}
LocationServices
.getFusedLocationProviderClient(this)
.requestLocationUpdates(request, locationCallback, Looper.getMainLooper())
initialized = true
}
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
super.onStartCommand(intent, flags, startId)
return START_STICKY
}
override fun onBind(intent: Intent?): IBinder? {
return null
}
override fun onDestroy() {
super.onDestroy()
LocationServiceRunning = false
if (initialized) {
LocationServices
.getFusedLocationProviderClient(this)
.removeLocationUpdates(locationCallback)
locationTimer.cancel()
}
if (Enabled) {
reportEvent("RESTARTING")
val broadcastIntent = Intent()
broadcastIntent.action = "restartservice"
broadcastIntent.setClass(this, LocationServiceRestarter::class.java)
this.sendBroadcast(broadcastIntent)
}
}
}
class LocationServiceRestarter : BroadcastReceiver() {
override fun onReceive(context: Context?, intent: Intent?) {
Log.i("?_LocationService", "LocationServiceRestarter triggered")
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
context!!.startForegroundService(Intent(context, LocationService::class.java))
} else {
context!!.startService(Intent(context, LocationService::class.java))
}
}
}
我可以在不完全重寫代碼的情況下避免這種記憶體泄漏嗎？
uj5u.com熱心網友回復：
消除
private lateinit var locationActivity: Activity
你需要的是一個Context，你的LocationService是一個Context。
改變
fun startLocationService(activity: Activity, enable: Boolean) { ... }
fun createNotification(activity: Activity, ...) { ... }
到
fun startLocationService(context: Context, enable: Boolean) { ... }
fun createNotification(context: Context, ...) { ... }
并呼叫createNotification傳遞作為第一個引數this而不是locationActivity.
您還可以使用applicationContext，而不是locationActivity當你打電話時已經這樣做startLocationService。
轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/324545.html