如何查看后台服务是否正在运行?
我想要一个切换服务状态的Android活动——它让我打开它,如果它是关闭的,如果它是关闭的。
如何查看后台服务是否正在运行?
我想要一个切换服务状态的Android活动——它让我打开它,如果它是关闭的,如果它是关闭的。
当前回答
检查服务是否正在运行的正确方法是简单地询问它。在您的服务中实现一个BroadcastReceiver来响应来自活动的ping。在服务启动时注册BroadcastReceiver,在服务被销毁时注销它。从您的活动(或任何组件)发送一个本地广播意图到服务,如果它响应,您就知道它正在运行。注意下面代码中ACTION_PING和ACTION_PONG之间的细微差别。
public class PingableService extends Service {
public static final String ACTION_PING = PingableService.class.getName() + ".PING";
public static final String ACTION_PONG = PingableService.class.getName() + ".PONG";
public int onStartCommand (Intent intent, int flags, int startId) {
LocalBroadcastManager.getInstance(this).registerReceiver(mReceiver, new IntentFilter(ACTION_PING));
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy () {
LocalBroadcastManager.getInstance(this).unregisterReceiver(mReceiver);
super.onDestroy();
}
private BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive (Context context, Intent intent) {
if (intent.getAction().equals(ACTION_PING)) {
LocalBroadcastManager manager = LocalBroadcastManager.getInstance(getApplicationContext());
manager.sendBroadcast(new Intent(ACTION_PONG));
}
}
};
}
public class MyActivity extends Activity {
private boolean isSvcRunning = false;
@Override
protected void onStart() {
LocalBroadcastManager manager = LocalBroadcastManager.getInstance(getApplicationContext());
manager.registerReceiver(mReceiver, new IntentFilter(PingableService.ACTION_PONG));
// the service will respond to this broadcast only if it's running
manager.sendBroadcast(new Intent(PingableService.ACTION_PING));
super.onStart();
}
@Override
protected void onStop() {
LocalBroadcastManager.getInstance(this).unregisterReceiver(mReceiver);
super.onStop();
}
protected BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive (Context context, Intent intent) {
// here you receive the response from the service
if (intent.getAction().equals(PingableService.ACTION_PONG)) {
isSvcRunning = true;
}
}
};
}
其他回答
对于kotlin,可以使用下面的代码。
fun isMyServiceRunning(calssObj: Class<SERVICE_CALL_NAME>): Boolean {
val manager = requireActivity().getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager
for (service in manager.getRunningServices(Integer.MAX_VALUE)) {
if (calssObj.getName().equals(service.service.getClassName())) {
return true
}
}
return false
}
同样,如果使用pending intent(例如使用AlarmManager),人们可能会发现另一种替代方法更干净:
public static boolean isRunning(Class<? extends Service> serviceClass) {
final Intent intent = new Intent(context, serviceClass);
return (PendingIntent.getService(context, CODE, intent, PendingIntent.FLAG_NO_CREATE) != null);
}
CODE是一个常量,您在类中私有地定义它,以标识与您的服务相关联的挂起意图。
你可以使用这个(我还没有尝试过,但我希望它能工作):
if(startService(someIntent) != null) {
Toast.makeText(getBaseContext(), "Service is already running", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(getBaseContext(), "There is no service running, starting service..", Toast.LENGTH_SHORT).show();
}
如果已经有一个正在运行的服务,startService方法将返回ComponentName对象。如果不是,则返回null。
参见公共抽象ComponentName startService (Intent服务)。
这和检查不一样,因为它正在启动服务,所以你可以添加stopService(someIntent);按照规定。
得到它!
你必须调用startService()为你的服务正确注册和传递BIND_AUTO_CREATE是不够的。
Intent bindIntent = new Intent(this,ServiceTask.class);
startService(bindIntent);
bindService(bindIntent,mConnection,0);
现在是ServiceTools类:
public class ServiceTools {
private static String LOG_TAG = ServiceTools.class.getName();
public static boolean isServiceRunning(String serviceClassName){
final ActivityManager activityManager = (ActivityManager)Application.getContext().getSystemService(Context.ACTIVITY_SERVICE);
final List<RunningServiceInfo> services = activityManager.getRunningServices(Integer.MAX_VALUE);
for (RunningServiceInfo runningServiceInfo : services) {
if (runningServiceInfo.service.getClassName().equals(serviceClassName)){
return true;
}
}
return false;
}
}
摘自Android文档:
比如sendBroadcast(Intent),但是如果有任何接收器 这个函数将阻塞并立即分发它们 返回之前。
你可以把这次入侵看成是"ping "服务。因为我们可以同步广播,所以我们可以在UI线程上同步广播并获得结果。
服务
@Override
public void onCreate() {
LocalBroadcastManager
.getInstance(this)
.registerReceiver(new ServiceEchoReceiver(), new IntentFilter("ping"));
//do not forget to deregister the receiver when the service is destroyed to avoid
//any potential memory leaks
}
private class ServiceEchoReceiver extends BroadcastReceiver {
public void onReceive (Context context, Intent intent) {
LocalBroadcastManager
.getInstance(this)
.sendBroadcastSync(new Intent("pong"));
}
}
活动
bool serviceRunning = false;
protected void onCreate (Bundle savedInstanceState){
LocalBroadcastManager.getInstance(this).registerReceiver(pong, new IntentFilter("pong"));
LocalBroadcastManager.getInstance(this).sendBroadcastSync(new Intent("ping"));
if(!serviceRunning){
//run the service
}
}
private BroadcastReceiver pong = new BroadcastReceiver(){
public void onReceive (Context context, Intent intent) {
serviceRunning = true;
}
}
当然,在许多应用程序中,赢家是服务上的静态布尔字段,在service . oncreate()中设置为true,在service . ondestroy()中设置为false,因为它要简单得多。