我有一个粘性服务（从START_STICKY返回onStartCommand），它在AsyncTask中执行了一些代码，但我在如何以及何时启动方面遇到了一些问题，绑定，停止，解除绑定。我只想在父活动活着期间提供服务，我不希望它在应用程序关闭时在后台闲逛，但我需要服务才能在方向更改后继续存在。我目前不需要在活动的整个持续时间内激活该服务，因此我在AsyncTask的{{1}}中完成主要工作后调用stopSelf（）然后启动需要时再次Service。有时我需要中断服务正在进行的工作，取消Service并使用不同的数据重新开始。问题在于，无论我做什么 - 我似乎无法在所有不同的场景中得到它。任何人都可以看看并告诉我我做错了什么？
我的AsyncTask是：
Service目前，我在创建自定义public class ChordCalculatorService extends Service {
private final IBinder mBinder = new LocalBinder();
private AsyncTask<SearchData, SearchStatusData, List<Item>> currentTask;
@Override
public void onCreate() {}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
/**
* Class for clients to access. Because we know this service always runs in
* the same process as its clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
public ChordCalculatorService getService() {
return ChordCalculatorService.this;
}
}
@Override
public void onDestroy() {
super.onDestroy();
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
public SearchData getSearchData() {
return searchData;
}
public void startWork() {
if (currentTask != null && currentTask.getStatus() == Status.RUNNING) {
currentTask.cancel(true);
}
if(searchData != null) {
Worker task = new Worker();
currentTask = task.execute(new SearchData[] { searchData });
} else {
Message msg = handler.obtainMessage(ERROR, "No search data set");
handler.sendMessage(msg);
}
}
class Worker extends AsyncTask<SearchData, SearchStatusData, List<Item>> {
// ... code ...
@Override
protected void onPostExecute(List<Item> result) {
Message msg = handler.obtainMessage(COMPLETE, new StatusData(Status.STATUS_FINISHED, result));
handler.sendMessage(msg);
stopSelf();
}
}
}
时启动了Service：
View并在public class MyCustomView extends BasicFretBoardView {
private ServiceConnection conn;
private MyService myService;
private boolean isServiceStarted;
private boolean isServiceBound;
public MyCustomView(Context context, AttributeSet attr) {
super(context, attr);
startService();
}
public void startService() {
Intent serviceIntent = new Intent(getContext(), MyService.class);
conn = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
myService = ((LocalBinder) service).getService();
myService.registerHandler(serviceHandler);
}
@Override
public void onServiceDisconnected(ComponentName name) {
myService = null;
}
};
// Explicitly start the service. Don't use BIND_AUTO_CREATE, since it
// causes an implicit service stop when the last binder is removed.
getContext().startService(serviceIntent);
getContext().bindService(serviceIntent, conn, 0);
isServiceStarted = true;
isServiceBound = true;
}
public void stopService() {
if (isServiceStarted) {
Intent serviceIntent = new Intent(getContext(), MyService.class);
getContext().stopService(serviceIntent);
isServiceStarted = false;
}
unBindService();
}
public void unBindService() {
if(isServiceBound) {
getContext().unbindService(conn);
isServiceBound = false;
}
}
// gets called based on some user interaction
private void startServiceWork() {
if(!isServiceStarted) {
startService();
} else {
myService.cancelCalcalation();
}
myService.setData(data);
myService.startWork();
}
}
：
Activity答案 0 :(得分：0)
似乎您希望您的任务按需运行，也许IntentService可能是更合适的选择。当您需要完成工作（startServiceWork（））时，您只需启动该服务即可启动AsyncTask。任务完成后，服务将完成。
现在，关于方向更改，您必须实现其意图过滤器为“android.intent.action.CONFIGURATION_CHANGED”的广播接收器。 （我假设您希望服务在方向更改时起作用）将广播接收器放在您的activity / main ui线程中。这实际上会使广播接收器的主机进程成为主要的应用程序进程，从而使从广播接收器内启动服务更安全。