System.Net.Http.WinHttpHandler.WinHttpHandler.SetRequestHandleProxyOptions C# (CSharp) Метод

        private void SetRequestHandleProxyOptions(WinHttpRequestState state)
        {
            // We've already set the proxy on the session handle if we're using no proxy or default proxy settings.
            // We only need to change it on the request handle if we have a specific IWebProxy or need to manually
            // implement Wininet-style auto proxy detection.
            if (state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseCustomProxy ||
                state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseWinInetProxy)
            {
                var proxyInfo = new Interop.WinHttp.WINHTTP_PROXY_INFO();
                bool updateProxySettings = false;
                Uri uri = state.RequestMessage.RequestUri;

                try
                {
                    if (state.Proxy != null)
                    {
                        Debug.Assert(state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseCustomProxy);
                        updateProxySettings = true;
                        if (state.Proxy.IsBypassed(uri))
                        {
                            proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NO_PROXY;
                        }
                        else
                        {
                            proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NAMED_PROXY;
                            Uri proxyUri = state.Proxy.GetProxy(uri);
                            string proxyString = proxyUri.Scheme + "://" + proxyUri.Authority;
                            proxyInfo.Proxy = Marshal.StringToHGlobalUni(proxyString);
                        }
                    }
                    else if (_proxyHelper != null && _proxyHelper.AutoSettingsUsed)
                    {
                        if (_proxyHelper.GetProxyForUrl(_sessionHandle, uri, out proxyInfo))
                        {
                            updateProxySettings = true;
                        }
                    }

                    if (updateProxySettings)
                    {
                        GCHandle pinnedHandle = GCHandle.Alloc(proxyInfo, GCHandleType.Pinned);

                        try
                        {
                            SetWinHttpOption(
                                state.RequestHandle,
                                Interop.WinHttp.WINHTTP_OPTION_PROXY,
                                pinnedHandle.AddrOfPinnedObject(),
                                (uint)Marshal.SizeOf(proxyInfo));
                        }
                        finally
                        {
                            pinnedHandle.Free();
                        }
                    }
                }
                finally
                {
                    Marshal.FreeHGlobal(proxyInfo.Proxy);
                    Marshal.FreeHGlobal(proxyInfo.ProxyBypass);
                }
            }
        }