基础连接已经关闭: 未能为 SSL/TLS 安全通道建立信任关系。

(转自：http://blog.sina.com.cn/s/blog_5eca668b01018949.html)
定义一个类，来对远程X.509证书的验证，进行处理，返回为true.我们要自己定义一个类，然后在客户单调用WCF服务之前，执行一次即可。代码如下：

public static class Util
{
   /// <summary>
   /// Sets the cert policy.
   /// </summary>
   public static void SetCertificatePolicy()
   {      
       ServicePointManager.ServerCertificateValidationCallback  += RemoteCertificateValidate;
   }
  /// <summary>
  /// Remotes the certificate validate.
  /// </summary>
  private static bool RemoteCertificateValidate( object sender, X509Certificate cert,  X509Chain chain, SslPolicyErrors error)
  {
      // trust any certificate!!!
      System.Console.WriteLine("Warning, trust any certificate");
      return true;
  }    
}

你要在调用操作点先调用这个方法： Util.SetCertificatePolicy();