无效的 URI:URI 方案在 aspx 中无效

Invalid URI: The URI scheme is not valid in aspx

当我在代码中对 url 进行硬编码时,它可以正常工作。我正在尝试获取主机名并附加请求。它给出了这个错误,

无效 URI: URI 方案无效。

说明: 当前网络请求执行过程中出现未处理的异常。请查看堆栈跟踪以获取有关错误及其在代码中的来源的更多信息。

Exception Details: System.UriFormatException: Invalid URI: The URI scheme is not valid.
Source Error: 
Line 44:         string request = url.Scheme + "//" + url.Host + ":" + url.Port +"/accounts1/asp2netbridge.asp?sessVar=";
Line 45:       
Line 46:         HttpWebRequest _myRequest = (HttpWebRequest)WebRequest.Create(new Uri(request + sessionValue));
Line 47:         _myRequest.ContentType = "text/html";
Line 48:         _myRequest.Credentials = CredentialCache.DefaultCredentials;

代码如下:

  Uri url = HttpContext.Current.Request.Url;
  string request = url.Scheme + "//" + url.Host + ":" + url.Port +"/accounts1/asp2netbridge.asp?sessVar=";      
  HttpWebRequest _myRequest = (HttpWebRequest)WebRequest.Create(new Uri(request + sessionValue));

在“//”之前添加“:”

string request = url.Scheme + "://" + url.Host + ":" + url.Port +"/accounts1/asp2netbridge.asp?sessVar=";