xamarin android 获取根证书代码

Java.Security.KeyStore keyStore = Java.Security.KeyStore.GetInstance("AndroidCAStore");

            keyStore.Load(null, null);

            Java.Util.IEnumeration keyAliases = keyStore.Aliases();

            while (keyAliases.HasMoreElements)

            {

                string alias = (string)keyAliases.NextElement();

                //系统默认CA开头为system  用户的为user

                if (alias.StartsWith("system"))

                {

                    Java.Security.Cert.X509Certificate cert2 = (Java.Security.Cert.X509Certificate)keyStore.GetCertificate(alias);

                    if (keyID == cert2.SerialNumber.ToString())

                    {

                        isTrustRoot = true;

                    }

                }

            }

 string keyID = cert.SerialNumber.ToString();

 System.Security.Cryptography.X509Certificates.X509Store store = new System.Security.Cryptography.X509Certificates.X509Store(System.Security.Cryptography.X509Certificates.StoreName.Root);

             store.Open(System.Security.Cryptography.X509Certificates.OpenFlags.ReadOnly);

             System.Security.Cryptography.X509Certificates.X509Certificate2Collection x509CertCollections = store.Certificates;

             var certs = store.Certificates.Find(System.Security.Cryptography.X509Certificates.X509FindType.FindBySerialNumber, keyID, true);

             if (certs.Count == )

             {

                 return false;

             }