通过活动呼叫服务方法

Question

I need to call a function from a service when a item from the options menu is pressed:

if (id == R.id.action_connect) {
    if (mIsBound) {
        LocalService.connect();
        // cannot be referenced from a static context
    }
}

I'm using these docs . I read a few answers but I'm not sure about this one.

Answer 1

You can call startService(someIntent);

For example from an activity you can do something like this

Intent serviceIntent = new Intent(this, TheService.class);
serviceIntent.addCategory("some_unique_string");
startService(serviceIntent);

Then in the service

public int onStartCommand(Intent intent, int flags, int startId) {
    if (intent != null) {
        if (intent.hasCategory("some_unique_string")) {
            theMethodYouWantToCall();   
        } else if (intent.hasCategory("some_other_string")) {
            someOtherMethod();
        }
    }

    return START_STICKY;
}

You can call startService as often as you like.

The basic idea is to create an intent that represents the "intended" method you want to call , then in the service onStartCommand method, figure out what method you should call based on the information you pass in via the intent and then call the method.

Note: You must check that the intent is not null. If the system ever kills and restarts your service, it will do so effectively calling startService with a null for the intent, so if you leave that part out you will at some point get NPE crash.

Answer 2

i don't have reputation to comment. but it is better to set an action instead of category. like

@Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        String action = intent.getAction();
        if (action.equals(ACTION_PLAY))
            processPlayRequest();
        else if (action.equals(ACTION_PAUSE))
            processPauseRequest();
        else if (action.equals(ACTION_SKIP))
            processSkipRequest();
        else if (action.equals(ACTION_STOP))
            processStopRequest();
        else if (action.equals(ACTION_REWIND))
            processRewindRequest();
        else if (action.equals(ACTION_URL))
            processAddRequest(intent);

        return START_NOT_STICKY; // Means we started the service, but don't want
                                 // it to
                                 // restart in case it's killed.
    }

And also add them in manifest like

<service
            android:exported="false"
            android:name="com.cibotechnology.KXNT.MusicService"
        >
            <intent-filter>
                <action
                    android:name="com.cibotechnology.KXNT.action.PLAY" />
                <action
                    android:name="com.cibotechnology.KXNT.action.PAUSE" />
                <action
                    android:name="com.cibotechnology.KXNT.action.SKIP" />
                <action
                    android:name="com.cibotechnology.KXNT.action.REWIND" />
                <action
                    android:name="com.cibotechnology.KXNT.action.STOP" />
            </intent-filter>
            <intent-filter>
                <action
                    android:name="com.cibotechnology.KXNT.action.URL" />
                <data
                    android:scheme="http" />
            </intent-filter>
        </service>

have a look at this and this