System.Net.WebSockets.WebSocketProtocolComponent.GetSupportedVersion C# (CSharp) Method

        internal static string GetSupportedVersion()
        {
            if (s_webSocketDllHandle.IsInvalid)
            {
                WebSocketValidate.ThrowPlatformNotSupportedException_WSPC();
            }

            SafeWebSocketHandle webSocketHandle = null;
            try
            {
                int errorCode = Interop.WebSocket.WebSocketCreateClientHandle(null, 0, out webSocketHandle);
                ThrowOnError(errorCode);

                if (webSocketHandle == null ||
                    webSocketHandle.IsInvalid)
                {
                    WebSocketValidate.ThrowPlatformNotSupportedException_WSPC();
                }

                IntPtr additionalHeadersPtr;
                uint additionalHeaderCount;

                errorCode = Interop.WebSocket.WebSocketBeginClientHandshake(webSocketHandle,
                    IntPtr.Zero,
                    0,
                    IntPtr.Zero,
                    0,
                    s_initialClientRequestHeaders,
                    (uint)s_initialClientRequestHeaders.Length,
                    out additionalHeadersPtr,
                    out additionalHeaderCount);
                ThrowOnError(errorCode);

                Interop.WebSocket.HttpHeader[] additionalHeaders = MarshalHttpHeaders(additionalHeadersPtr, (int)additionalHeaderCount);

                string version = null;
                foreach (Interop.WebSocket.HttpHeader header in additionalHeaders)
                {
                    if (string.Compare(header.Name,
                            HttpKnownHeaderNames.SecWebSocketVersion,
                            StringComparison.OrdinalIgnoreCase) == 0)
                    {
                        version = header.Value;
                        break;
                    }
                }
                Debug.Assert(version != null, "'version' MUST NOT be NULL.");

                return version;
            }
            finally
            {
                if (webSocketHandle != null)
                {
                    webSocketHandle.Dispose();
                }
            }
        }