未能創建 SSL/TLS 安全通道

服務端用了自簽名證書，客戶端需帶上證書去請求

                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);//驗證服務器證書回調自動驗證
                X509Certificate cer1 = new X509Certificate("client.pfx", "123456");
                request.ClientCertificates.Add(cer1);

public static bool CheckValidationResult(object sender, System.Security.Cryptography.X509Certificates.X509Certificate certificate,
System.Security.Cryptography.X509Certificates.X509Chain chain, System.Net.Security.SslPolicyErrors errors)
{ // 總是接受
return true;
}

試了很多方法總是報“未能創建 SSL/TLS 安全通道”等錯誤

解決步驟：

1.安裝證書到本地計算機賬號

2.將項目.net版本升到4.6