How to start android service from another Android

问题:

I'm having a problem starting a service from another Android app (API 17). However, if I do run 'am' from the shell, the service starts fine.

# am startservice com.xxx.yyy/.SyncService
Starting service: Intent { act=android.intent.action.MAIN cat=
[android.intent.category.LAUNCHER] cmp=com.xxx.yyy/.SyncService }
(service starts fine at this point)
# am to-intent-uri com.xxx.yyy/.SyncService
intent:#Intent;action=android.intent.action.MAIN;
category=android.intent.category.LAUNCHER;
component=com.xxx.yyy/.SyncService;end

So, it doesn't look like I'm missing anything from the intent when I do the same in the code:

Intent i = new Intent();
i.setAction(Intent.ACTION_MAIN);
i.addCategory(Intent.CATEGORY_LAUNCHER);
i.setComponent(new ComponentName("com.xxx.yyy", ".SyncService"));
ComponentName c = ctx.startService(i);
if (c == null) { Log.e(TAG, "failed to start with "+i); }

What I get is (the service is not running at that time):

E/tag( 4026): failed to start with Intent { 
act=android.intent.action.MAIN 
cat=[android.intent.category.LAUNCHER] 
cmp=com.xxx.yyy/.SyncService }

I don't have an intent filter on the service, and I don't want to set one up, I'm really trying to understand what am I doing wrong starting it through its component name, or what may be making it impossible to do so.

回答1:

You should be able to start your service like this:

Intent i = new Intent();
i.setComponent(new ComponentName("com.xxx.yyy", "com.xxx.yyy.SyncService"));
ComponentName c = ctx.startService(i);

You don't need to set ACTION or CATEGORY if you are specifying a specific component. Make sure that your service is properly defined in the manifest.