get app version code from androidmanifest

public String getVersionCode(Context context, Class<?> cls) {
        try {
            ComponentName component = new ComponentName(context, cls);
            PackageInfo info = context.getPackageManager().getPackageInfo(component.getPackageName(), 0);
            return "" + info.versionCode;
        } catch (android.content.pm.PackageManager.NameNotFoundException e) {
            return "0";
        }
    }