c# – 选择具有多个IP(.NET)时HTTP请求使用的IP

string sendingIp = "192.168.0.1";
int sendingPort = 5000;
Uri uri = new Uri("http://google.com");
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(uri);
ServicePoint sp = ServicePointManager.FindServicePoint(uri);
sp.BindIPEndPointDelegate =
    (servicePoint,remoteEp,retryCount) =>
         {
             return new IPEndPoint(IPAddress.Parse(sendingIp),sendingPort);
         };
var data = new StreamReader(wr.GetResponse().GetResponseStream()).ReadToEnd();

此代码不能正确处理.