[Xamarin] Android 시리얼 번호 가져오기 (10버전 이하용)

private string GetDeviceSerialNumber()         {             // https://gist.github.com/flawyte/efd23dd520fc2320f94ba003b9aabfce             try             {                 Java.Lang.String sn = null;                 Java.Lang.Class c = Java.Lang.Class.ForName("android.os.SystemProperties");                 Method get = c.GetMethod("get", Java.Lang.Class.FromType(typeof(Java.Lang.String)));                   sn = (Java.Lang.String)(get.Invoke(c, "sm.sn1"));                   if (string.IsNullOrEmpty(sn.ToString()))                 {                     sn = (Java.Lang.String)(get.Invoke(c, "gsm.sn1"));                 }                   if (string.IsNullOrEmpty(sn.ToString()))                 {                     sn = (Java.Lang.String)(get.Invoke(c, "ril.serialnumber"));                 }                                  if (string.IsNullOrEmpty(sn.ToString()))                 {                     sn = (Java.Lang.String)(get.Invoke(c, "sys.serialnumber"));                 }                   if (string.IsNullOrEmpty(sn.ToString()))                 {                     sn = (Java.Lang.String)(get.Invoke(c, "ro.serialno"));                 }                   if (sn == null)                     return "";                   else                     return sn.ToString();             }               catch (global::Java.Lang.Exception ex)             {                 return "";             }         }