1 - there are Android devices for Android.
No, not all devices have Google Play services installed by default.
2 - , ?
3 - - , ,
, Google Play GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);, , Google Play Google Play.
- :
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS) {
if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
GooglePlayServicesUtil.getErrorDialog(resultCode, this,
PLAY_SERVICES_RESOLUTION_REQUEST).show();
} else {
Log.i(TAG, "This device is not supported.");
finish();
}
}
: http://developer.android.com/google/play-services/setup.html#ensure