.net 4.0 以下HttpWebRequest Header 修改hosts方法

.net 4.0 以下HttpWebRequest Header 修改hosts方法 特此记录

  public class CusteredHeaderCollection : WebHeaderCollection
     {
         public bool HostHeaderValueReplaced { get; private set; }

         public string ClusterUrl { get; private set; }

         public CusteredHeaderCollection(string commonClusterUrl) : base()
         {
             if (string.IsNullOrEmpty("commonClusterUrl"))
                 throw new ArgumentNullException("commonClusterUrl");

             this.ClusterUrl = commonClusterUrl;
         }

         public override string ToString()
         {
             this["Host"] = this.ClusterUrl;
             string tmp = base.ToString();
             this.HostHeaderValueReplaced = true;

             return tmp;
         }

     }

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);

   FieldInfo headersFieldInfo = request.GetType().GetField("_HttpRequestHeaders", System.Reflection.BindingFlags.NonPublic
                                                    | System.Reflection.BindingFlags.Instance
                                                    | System.Reflection.BindingFlags.GetField);

                 CusteredHeaderCollection WssHeaders = new CusteredHeaderCollection(sDomain);

                 headersFieldInfo.SetValue(request, WssHeaders);

                 request.Proxy = null;