android - GCM register return empty reg id -

android - GCM register return empty reg id -

i'm trying force notification application , in origin stage-registration. next code give empty id in register()...probably have not much thought on gcm...what's going on?

private class backgroundregister extends asynctask<void,void,string>{ @override protected string doinbackground(void... params) { // todo auto-generated method stub string regid = ""; googlecloudmessaging gcm = googlecloudmessaging.getinstance(activity); seek { regid = gcm.register(project_id); log.d("reg id", regid+""); if (regid == null || regid.isempty()){ homecoming ""; } else { storeregistrationid(regid); log.d("register", getregid()+" registered"); } } grab (ioexception e) { // todo auto-generated grab block e.printstacktrace(); } homecoming regid; } }

android google-cloud-messaging