Android APN Enforcement

问题:

Someone know if there's a programmatically way to use a specific defined APN on the device which is not the default one?

Thanks.

回答1:

You can programmatically query and set the preferred APN using the uri content://telephony/carriers/preferapn. To set a new preferred APN you have to pass in the database ID of an existing APN entry. The following function can do this if you pass in the display name of the APN (eg: setPreferredApn(context, "Giffgaff");)

public static final Uri APN_TABLE_URI = Uri.parse("content://telephony/carriers");
public static final Uri APN_PREFER_URI = Uri.parse("content://telephony/carriers/preferapn");

public static boolean setPreferredApn(Context context, String name) {
    boolean changed = false;
    String columns[] = new String[] { Carriers._ID, Carriers.NAME };
    String where = "name = ?";
    String wargs[] = new String[] {name};
    String sortOrder = null;
    Cursor cur = context.getContentResolver().query(APN_TABLE_URI, columns, where, wargs, sortOrder);
    if (cur != null) {
        if (cur.moveToFirst()) {
            ContentValues values = new ContentValues(1);
            values.put("apn_id", cur.getLong(0));
            if (context.getContentResolver().update(APN_PREFER_URI, values, null, null) == 1)
                changed = true;
        }
        cur.close();
    }
    return changed;
}

I guess I should add that you need WRITE_APN_SETTINGS permission and need to import android.provider.Telephony and android.provider.Telephony.Carriers

UPDATE FOR 4.0+

This facility became disabled with the release of Android 4.0 (ICS). Enabling the WRITE_APN_SETTINGS permission has no effect on allowing you to set the APN any more. See this question for some relevant links. On the API page it now states explicitly this permission is not for external use and this is enforced internally.

回答2:

I dont think there is a way, even if there is one, the carrier could wipe it out with a software update. Also, for some carriers like AT&T in US, using a specific APN provides specific functionality, like getting the Subscriber number of that user (its a unique ID, not the phone number). So it may not be a good idea to force this change, as it will impact numerous other apps installed on handset.