首先加上引用“System.Security.DLL”，其次在工程中

using System.Security.Cryptography.X509Certificates;

這樣就可以使用“

X509Certificate Class

之後我們就可以

///構建請求的HttpWebRequest物件

HttpWebRequest hwrRequest = (HttpWebRequest)WebRequest.Create(

                                   strValidatePageURL);

/// 從本地檔案中載入證書

hwrRequest.ClientCertificates.Add(X509Certificate.CreateFromCertFile("c://motor.https.pem.cer"));

這是一個較簡單的辦法。

如果你遇到了“The underlying connection was closed. Could not establish a secure SSL/TLS connection"”的異常，那麼請設定

hwrRequest.KeepAlive = true;

至於如何“在個人證書儲存區獲取證書”