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

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。

其他回答

这更适用于Intent Service调试,因为它们会生成一个线程,但也适用于常规服务。我找到这个线程感谢宾

在我的例子中,我摆弄了调试器并找到了线程视图。它看起来有点像微软Word里的项目符号图标。无论如何,您不必在调试器模式下使用它。单击该流程并单击该按钮。任何Intent服务都会在运行时显示出来,至少在模拟器上是这样。

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;
            }
        }
    };
}

在serviceclass内部定义:

 public static Boolean serviceRunning = false;

然后在onStartCommand(…)

 public int onStartCommand(Intent intent, int flags, int startId) {

    serviceRunning = true;
    ...
}

 @Override
public void onDestroy()
{
    serviceRunning = false;

} 

然后,调用if(serviceclass。serviceRunning == true)。

/**
 * Check if the service is Running 
 * @param serviceClass the class of the Service
 *
 * @return true if the service is running otherwise false
 */
public boolean checkServiceRunning(Class<?> serviceClass){
    ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE))
    {
        if (serviceClass.getName().equals(service.service.getClassName()))
        {
            return true;
        }
    }
    return false;
}

在你的服务子类中,使用一个静态布尔值来获取服务的状态,如下所示。

MyService.kt

class MyService : Service() {
    override fun onCreate() {
        super.onCreate()
        isServiceStarted = true
    }
    override fun onDestroy() {
        super.onDestroy()
        isServiceStarted = false
    }
    companion object {
        var isServiceStarted = false
    }
}

MainActivity.kt

class MainActivity : AppCompatActivity(){
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val serviceStarted = FileObserverService.isServiceStarted
        if (!serviceStarted) {
            val startFileObserverService = Intent(this, FileObserverService::class.java)
            ContextCompat.startForegroundService(this, startFileObserverService)
        }
    }
}