如何让 Url.Action 使用正确的端口号？

Question

我正在使用 MVC3 创建一个网站，我使用 razor 语法来创建视图，并且所有这些都在 azure 下运行。

目前我在本地的azure模拟器下运行。

我在网址上有一个视图：'http://localhost:81/Blah/Foo'。

在该视图中，我想获取另一个操作的 Url。

为了实现这一点，我使用： Url.Action("SomeAction", "SomeController", null, this.Request.Url.Scheme)

但是，由于负载平衡，azure 模拟器会更改请求的端口号。

即，当它在端口 81 上运行时，请求可能来自端口 82。

这会导致创建不正确的 url 'http: //localhost:82/Blah/Bar'，我收到 400 错误主机名错误。

按照这篇文章中的信息http://social.msdn.microsoft.com/Forums/en-US/windowsazure/thread/9142db8d-0f85-47a2-91f7-418bb5a0c675/ 我发现我可以获得正确的结果使用 HttpContext.Request.Headers["Host"] 的主机和端口号。

但我只能将主机名传递给 Url.Action，如果我尝试传递主机名和端口，那么它仍然会附加它认为正确的端口，所以我最终会得到 localhost:81:82。

编辑：我发现有人有同样的问题。他们似乎收集了与我相同的信息（除了他们也包含了复制品），但他们没有有用的修复，因为我无法手动指定端口号。

http://social.msdn.microsoft.com/Forums/en-US/windowsazuredevelopment/thread/87c729e8-094c-4578-b9d1-9c8ff7311577/

我想一个解决办法是我自己的 Url.Action 重载让我可以指定端口。

Answer 1

对于来到这里的每个实际上需要绝对路径并且支持负载平衡系统的人，这就是我想到的：

//http://stackoverflow.com/questions/126242/how-do-i-turn-a-relative-url-into-a-full-url
public static string AbsoluteAction(this UrlHelper url, string actionName, string controllerName, object routeValues = null)
{
  Uri publicFacingUrl = GetPublicFacingUrl(url.RequestContext.HttpContext.Request, url.RequestContext.HttpContext.Request.ServerVariables);
  string relAction = url.Action(actionName, controllerName, routeValues);
  //this will always have a / in front of it.
  var newPort = publicFacingUrl.Port == 80 || publicFacingUrl.Port == 443 ? "" : ":"+publicFacingUrl.Port.ToString();
  return publicFacingUrl.Scheme + Uri.SchemeDelimiter + publicFacingUrl.Host + newPort + relAction;
}

然后，来自 https://github.com/aarnott/dotnetopenid/blob/v3.4/src/DotNetOpenAuth/Messaging/HttpRequestInfo.cs 通过 http://go4answers.webhost4life.com/Example/azure-messing-port-numbers-creates-28516.aspx

   /// <summary>
    /// Gets the public facing URL for the given incoming HTTP request.
    /// </summary>
    /// <param name="request">The request.</param>
    /// <param name="serverVariables">The server variables to consider part of the request.</param>
    /// <returns>
    /// The URI that the outside world used to create this request.
    /// </returns>
    /// <remarks>
    /// Although the <paramref name="serverVariables"/> value can be obtained from
    /// <see cref="HttpRequest.ServerVariables"/>, it's useful to be able to pass them
    /// in so we can simulate injected values from our unit tests since the actual property
    /// is a read-only kind of <see cref="NameValueCollection"/>.
    /// </remarks>
internal static Uri GetPublicFacingUrl(HttpRequestBase request, NameValueCollection serverVariables)
{
  //Contract.Requires<ArgumentNullException>(request != null);
  //Contract.Requires<ArgumentNullException>(serverVariables != null);

  // Due to URL rewriting, cloud computing (i.e. Azure)
  // and web farms, etc., we have to be VERY careful about what
  // we consider the incoming URL.  We want to see the URL as it would
  // appear on the public-facing side of the hosting web site.
  // HttpRequest.Url gives us the internal URL in a cloud environment,
  // So we use a variable that (at least from what I can tell) gives us
  // the public URL:
  if (serverVariables["HTTP_HOST"] != null)
  {
    //ErrorUtilities.VerifySupported(request.Url.Scheme == Uri.UriSchemeHttps || request.Url.Scheme == Uri.UriSchemeHttp, "Only HTTP and HTTPS are supported protocols.");
    string scheme = serverVariables["HTTP_X_FORWARDED_PROTO"] ?? request.Url.Scheme;
    Uri hostAndPort = new Uri(scheme + Uri.SchemeDelimiter + serverVariables["HTTP_HOST"]);
    UriBuilder publicRequestUri = new UriBuilder(request.Url);
    publicRequestUri.Scheme = scheme;
    publicRequestUri.Host = hostAndPort.Host;
    publicRequestUri.Port = hostAndPort.Port; // CC missing Uri.Port contract that's on UriBuilder.Port
    return publicRequestUri.Uri;
  }
  // Failover to the method that works for non-web farm enviroments.
  // We use Request.Url for the full path to the server, and modify it
  // with Request.RawUrl to capture both the cookieless session "directory" if it exists
  // and the original path in case URL rewriting is going on.  We don't want to be
  // fooled by URL rewriting because we're comparing the actual URL with what's in
  // the return_to parameter in some cases.
  // Response.ApplyAppPathModifier(builder.Path) would have worked for the cookieless
  // session, but not the URL rewriting problem.
  return new Uri(request.Url, request.RawUrl);
}

Answer 2

如果你只使用 Url.Action("Action", "Controller") 会发生什么？这应该只是生成一个相对 URL，它应该可以工作。

（或者也许更好的问题是：你为什么不使用那个重载？）

Answer 3

我发现这对我有用......

var request = HttpContext.Request;
string url = request.Url.Scheme + "://" +
             request.UserHostAddress +  ":" +
             request.Url.Port;