我使用的C＃/。NET应用程序具有与外部Web服务集成的功能。对于通信，我们利用从.NET System.Net.WebClient类继承的类构建。
在尝试从彭博网站检索WSDL进行测试时，我们似乎已断开连接，而没有其他指示。看起来好像获得了成功的HTTPS连接，但是当尝试读取响应时，远程站点只是断开连接。我们只是调用System.Net.WebClient.DownloadString()方法并传递WSDL URL：https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL。
webClient = new HttpWebClient();
UriBuilder uriBuilder = new UriBuilder(this.ServiceUrl);
uriBuilder.Query = "WSDL";
webClient.Headers.Add("Content-Type", "text/xml; charset=utf-8");
this.RawWsdlData = webClient.DownloadString(uriBuilder.Uri);
通过将相同的URL放入浏览器中，我们已经能够验证URL是否正确，从而使我们获得了所请求的WSDL。
我已打开System.Net跟踪，并且能够获取内部跟踪。请注意，HttpWebClient是我们从System.Net.WebClient继承的类。
Log started for PID = 6564, TID = 26
Getting WSDL from service (https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL)
System.Net Verbose: 0 : [2072] Entering HttpWebClient#21999770::DownloadString(https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL#-917497223)
System.Net Verbose: 0 : [2072] Entering HttpWebClient#21999770::DownloadData(https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL#-917497223)
System.Net Verbose: 0 : [2072] Entering WebRequest::Create(https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL)
System.Net Verbose: 0 : [2072] Entering HttpWebRequest#49164730::HttpWebRequest(https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL#-917497223)
System.Net Information: 0 : [2072] Current OS installation type is 'Client'.
System.Net Information: 0 : [2072] RAS supported: True
System.Net Verbose: 0 : [2072] Exiting HttpWebRequest#49164730::HttpWebRequest()
System.Net Verbose: 0 : [2072] Exiting WebRequest::Create() -> HttpWebRequest#49164730
System.Net Verbose: 0 : [2072] Entering HttpWebRequest#49164730::GetResponse()
System.Net Error: 0 : [2072] Can't retrieve proxy settings for Uri 'https://service.bloomberg.com/assets/dl/dlws.wsdl?WSDL'. Error code: 12180.
System.Net Verbose: 0 : [2072] Entering ServicePoint#10615457::ServicePoint(service.bloomberg.com:443)
System.Net Information: 0 : [2072] Associating HttpWebRequest#49164730 with ServicePoint#10615457
System.Net Information: 0 : [2072] Associating Connection#16234150 with HttpWebRequest#49164730
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#24691947::Socket(AddressFamily#2)
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#24691947::Socket()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#7067698::Socket(AddressFamily#23)
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#7067698::Socket()
System.Net.Sockets Verbose: 0 : [2072] Entering DNS::TryInternalResolve(service.bloomberg.com)
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#24691947::Connect(69.191.242.179:443#-1275937026)
System.Net.Sockets Information: 0 : [2072] Socket#24691947 - Created connection from 10.2.7.102:52684 to 69.191.242.179:443.
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#24691947::Connect()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#7067698::Close()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#7067698::Dispose()
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#7067698::Close()
System.Net Information: 0 : [2072] Connection#16234150 - Created connection from 10.2.7.102:52684 to 69.191.242.179:443.
System.Net Information: 0 : [2072] TlsStream#32181663::.ctor(host=service.bloomberg.com, #certs=0, checkCertificateRevocationList=False, sslProtocols=Default)
System.Net Information: 0 : [2072] Associating HttpWebRequest#49164730 with ConnectStream#18140357
System.Net Information: 0 : [2072] HttpWebRequest#49164730 - Request: GET /assets/dl/dlws.wsdl?WSDL HTTP/1.1
System.Net Information: 0 : [2072] ConnectStream#18140357 - Sending headers
{
Content-Type: text/xml; charset=utf-8
Host: service.bloomberg.com
Connection: Keep-Alive
}.
System.Net Information: 0 : [2072] SecureChannel#31141938::.ctor(hostname=service.bloomberg.com, #clientCertificates=0, encryptionPolicy=RequireEncryption)
System.Net Information: 0 : [2072] Enumerating security packages:
System.Net Information: 0 : [2072] Negotiate
System.Net Information: 0 : [2072] NegoExtender
System.Net Information: 0 : [2072] Kerberos
System.Net Information: 0 : [2072] NTLM
System.Net Information: 0 : [2072] TSSSP
System.Net Information: 0 : [2072] pku2u
System.Net Information: 0 : [2072] WDigest
System.Net Information: 0 : [2072] Schannel
System.Net Information: 0 : [2072] Microsoft Unified Security Protocol Provider
System.Net Information: 0 : [2072] Default TLS SSP
System.Net Information: 0 : [2072] CREDSSP
System.Net Information: 0 : [2072] SecureChannel#31141938 - Left with 0 client certificates to choose from.
System.Net Information: 0 : [2072] SecureChannel#31141938::.AcquireClientCredentials, new SecureCredential() (flags=(ValidateManual, NoDefaultCred, SendAuxRecord), m_ProtocolFlags=(Ssl3Client, Tls10Client), m_EncryptionPolicy=RequireEncryption)
System.Net Information: 0 : [2072] AcquireCredentialsHandle(package = Microsoft Unified Security Protocol Provider, intent = Outbound, scc = System.Net.SecureCredential)
System.Net Information: 0 : [2072] InitializeSecurityContext(credential = System.Net.SafeFreeCredential_SECURITY, context = (null), targetName = service.bloomberg.com, inFlags = ReplayDetect, SequenceDetect, Confidentiality, AllocateMemory, InitManualCredValidation)
System.Net Information: 0 : [2072] InitializeSecurityContext(In-Buffer length=0, Out-Buffer length=125, returned code=ContinueNeeded).
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#24691947::Send()
System.Net.Sockets Verbose: 0 : [2072] Data from Socket#24691947::Send
System.Net.Sockets Verbose: 0 : [2072] 00000000 : 16 03 01 00 78 01 00 00-74 03 01 5C C2 03 9A 43 : ....x...t..\...C
System.Net.Sockets Verbose: 0 : [2072] 00000010 : 54 67 9D 98 2C 4E 6B B9-A4 4C D5 8D 08 BC 03 36 : Tg..,Nk..L.....6
System.Net.Sockets Verbose: 0 : [2072] 00000020 : 03 5F E6 D2 DA 82 2E AC-C4 C8 15 00 00 0E C0 0A : ._..............
System.Net.Sockets Verbose: 0 : [2072] 00000030 : C0 09 C0 14 C0 13 00 35-00 2F 00 0A 01 00 00 3D : .......5./.....=
System.Net.Sockets Verbose: 0 : [2072] 00000040 : 00 00 00 1A 00 18 00 00-15 73 65 72 76 69 63 65 : .........service
System.Net.Sockets Verbose: 0 : [2072] 00000050 : 2E 62 6C 6F 6F 6D 62 65-72 67 2E 63 6F 6D 00 0A : .bloomberg.com..
System.Net.Sockets Verbose: 0 : [2072] 00000060 : 00 08 00 06 00 1D 00 17-00 18 00 0B 00 02 01 00 : ................
System.Net.Sockets Verbose: 0 : [2072] 00000070 : 00 23 00 00 00 17 00 00-FF 01 00 01 00 : .#...........
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#24691947::Send() -> Int32#125
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#24691947::Receive()
System.Net.Sockets Error: 0 : [2072] Socket#24691947::UpdateStatusAfterSocketError() - ConnectionReset
System.Net.Sockets Error: 0 : [2072] Exception in Socket#24691947::Receive - An existing connection was forcibly closed by the remote host.
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#24691947::Receive() -> Int32#0
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#24691947::Dispose()
System.Net Error: 0 : [2072] Exception in HttpWebRequest#49164730:: - The underlying connection was closed: An unexpected error occurred on a send..
System.Net Information: 0 : [2072] Associating HttpWebRequest#49164730 with ServicePoint#10615457
System.Net Information: 0 : [2072] Associating Connection#39028125 with HttpWebRequest#49164730
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#26207244::Socket(AddressFamily#2)
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#26207244::Socket()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#38017319::Socket(AddressFamily#23)
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#38017319::Socket()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#26207244::Connect(69.191.242.179:443#-1275937026)
System.Net.Sockets Information: 0 : [2072] Socket#26207244 - Created connection from 10.2.7.102:52685 to 69.191.242.179:443.
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#26207244::Connect()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#38017319::Close()
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#38017319::Dispose()
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#38017319::Close()
System.Net Information: 0 : [2072] Connection#39028125 - Created connection from 10.2.7.102:52685 to 69.191.242.179:443.
System.Net Information: 0 : [2072] TlsStream#50247169::.ctor(host=service.bloomberg.com, #certs=0, checkCertificateRevocationList=False, sslProtocols=Default)
System.Net Information: 0 : [2072] Associating HttpWebRequest#49164730 with ConnectStream#41123459
System.Net Information: 0 : [2072] HttpWebRequest#49164730 - Request: GET /assets/dl/dlws.wsdl?WSDL HTTP/1.1
System.Net Information: 0 : [2072] ConnectStream#41123459 - Sending headers
{
Content-Type: text/xml; charset=utf-8
Host: service.bloomberg.com
Connection: Keep-Alive
}.
System.Net Information: 0 : [2072] SecureChannel#53272024::.ctor(hostname=service.bloomberg.com, #clientCertificates=0, encryptionPolicy=RequireEncryption)
System.Net Information: 0 : [2072] SecureChannel#53272024 - Left with 0 client certificates to choose from.
System.Net Information: 0 : [2072] Using the cached credential handle.
System.Net Information: 0 : [2072] InitializeSecurityContext(credential = System.Net.SafeFreeCredential_SECURITY, context = (null), targetName = service.bloomberg.com, inFlags = ReplayDetect, SequenceDetect, Confidentiality, AllocateMemory, InitManualCredValidation)
System.Net Information: 0 : [2072] InitializeSecurityContext(In-Buffer length=0, Out-Buffer length=125, returned code=ContinueNeeded).
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#26207244::Send()
System.Net.Sockets Verbose: 0 : [2072] Data from Socket#26207244::Send
System.Net.Sockets Verbose: 0 : [2072] 00000000 : 16 03 01 00 78 01 00 00-74 03 01 5C C2 03 9A D8 : ....x...t..\....
System.Net.Sockets Verbose: 0 : [2072] 00000010 : 38 E3 3A 39 65 29 89 69-19 11 28 40 22 A3 87 9F : 8.:9e).i..(@"...
System.Net.Sockets Verbose: 0 : [2072] 00000020 : 0C 7A 2D C6 9F 0A 67 D9-F1 78 CA 00 00 0E C0 0A : .z-...g..x......
System.Net.Sockets Verbose: 0 : [2072] 00000030 : C0 09 C0 14 C0 13 00 35-00 2F 00 0A 01 00 00 3D : .......5./.....=
System.Net.Sockets Verbose: 0 : [2072] 00000040 : 00 00 00 1A 00 18 00 00-15 73 65 72 76 69 63 65 : .........service
System.Net.Sockets Verbose: 0 : [2072] 00000050 : 2E 62 6C 6F 6F 6D 62 65-72 67 2E 63 6F 6D 00 0A : .bloomberg.com..
System.Net.Sockets Verbose: 0 : [2072] 00000060 : 00 08 00 06 00 1D 00 17-00 18 00 0B 00 02 01 00 : ................
System.Net.Sockets Verbose: 0 : [2072] 00000070 : 00 23 00 00 00 17 00 00-FF 01 00 01 00 : .#...........
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#26207244::Send() -> Int32#125
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#26207244::Receive()
System.Net.Sockets Error: 0 : [2072] Socket#26207244::UpdateStatusAfterSocketError() - ConnectionReset
System.Net.Sockets Error: 0 : [2072] Exception in Socket#26207244::Receive - An existing connection was forcibly closed by the remote host.
System.Net.Sockets Verbose: 0 : [2072] Exiting Socket#26207244::Receive() -> Int32#0
System.Net.Sockets Verbose: 0 : [2072] Entering Socket#26207244::Dispose()
System.Net Error: 0 : [2072] Exception in HttpWebRequest#49164730:: - The underlying connection was closed: An unexpected error occurred on a send..
System.Net Error: 0 : [2072] Exception in HttpWebRequest#49164730::GetResponse - The underlying connection was closed: An unexpected error occurred on a send..
System.Net Verbose: 0 : [2072] Entering HttpWebRequest#49164730::Abort()
System.Net Error: 0 : [2072] Exception in HttpWebRequest#49164730:: - The request was aborted: The request was canceled..
System.Net Verbose: 0 : [2072] Exiting HttpWebRequest#49164730::Abort()
作为HTTPS连接，我本来希望看到SSL / TLS类型错误，但这仅显示了远程断开连接，没有其他内容。
任何人对于可能的原因或进一步的调试方法都有任何想法吗？我可以随意复制它，所以这不是一个随机的问题。