问题
In my Android app, I call both startService and bindService:
Intent intent = new Intent(this, MyService.class);
ServiceConnection conn = new ServiceConnection() { ... }
startService(intent)
bindService(intent, conn, BIND_AUTO_CREATE);
Later, I attempt to both unbindService andstopService`:
unbindService(conn);
stopService(intent);
However, I get an exception on the call to unbindService. If I remove this call, the app seems to run properly through the stopService call.
Am I doing something wrong? I thought a bindService call had to be associated with an unbindService call, and a startService call had to be associated with a stopService call. This doesn't seem to be the case here, though.
回答1:
The Android documentation for stopService() states:
Note that if a stopped service still has ServiceConnection objects bound to it with the BIND_AUTO_CREATE set, it will not be destroyed until all of these bindings are removed. See the Service documentation for more details on a service's lifecycle.
So calling stopService() first followed by unbindService() should work (it's working for me).
回答2:
A gotcha that I hit with this:
Ensure you call unbindService on the same context that you called bindService. In my case, I was doing the following to bind it:
Context c = getApplicationContext();
c.bindService(...);
Then to unbind it, just:
unbindService(...);
Making sure both bind and unbind used the same context solved the problem.
回答3:
As you can see here it depends what you want to achieve and how you bind the service. If you want to have a long time reference to the service, it is better to use bindService than startService. If in the bindService method, the flag BIND_AUTO_CREATE is used, then you don't have to call startService, because the service starts itself when necessary.
If you call unBind service, then you assoication to the service is deleted. You dont' have to explicitly stop the service but you can. But it's importatnt to note, that if you call unBind(), then the service is allowed to stop at any time.
回答4:
To answer you question directly, it is "okay" to not call unbindservice BUT it is not recommended. What happens is if your service is not a foreground service, android system may kills it to free up memory. And if there is still some component bounded to it, but you haven't called unbind, it gets unbound by the android system.
See android documentation here
https://developer.android.com/guide/components/bound-services
If your client is still bound to a service when your app destroys the client, destruction causes the client to unbind. It is better practice to unbind the client as soon as it is done interacting with the service. Doing so allows the idle service to shut down. For more information about appropriate times to bind and unbind, see Additional notes.
来源：https://stackoverflow.com/questions/3385554/do-i-need-to-call-both-unbindservice-and-stopservice-for-android-services