C# 从网页中读取JSON一开始会抛出错误，但之后会起作用

我有一个从网页获取JSON字符串并对其进行解析的应用程序，等等。我遇到的问题是，第一次运行该应用程序时会抛出以下错误：

A first chance exception of type 'System.Net.Http.HttpRequestException' occurred in mscorlib.dll An error occurred while sending the request. System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 128.0.46.69:80 at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult) at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception) --- End of inner exception stack trace --- at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar) 我使用了splitpage模板。我也在MSDN上发布了这个问题，但我得到的唯一答案是版主说我的网络或我尝试访问的webvpage有问题

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我的网络和网页都没有问题第一次总是第二次，这真的很奇怪。

您在清单上添加了专用网络访问（

privateNetworkClientServer

）吗？是的，我已经添加了。同样的问题，之后我删除了它…同样的问题为什么你会担心第一次机会的例外？忽略它们。我不希望这样做，因为它可能会在应用程序向公众发布后的第一次启动时造成问题。

private async Task GetSampleDataAsync()
        {
            if (this._groups.Count != 0) return;
            int loopNo = 0;
            while (true)
            {
                loopNo++;
                try
                {
                    // Fetchibg JSON file from http
                    var client = new HttpClient();
                    HttpResponseMessage response = await client.GetAsync(new Uri("http://etc/data.php"));

                    var jsonString = await response.Content.ReadAsStringAsync();
                    JsonObject jsonObject = JsonObject.Parse(jsonString);
                    JsonArray jsonArray = jsonObject["Groups"].GetArray();

                    foreach (JsonValue groupValue in jsonArray)
                    {
                        JsonObject groupObject = groupValue.GetObject();
                        SampleDataGroup group = new SampleDataGroup(groupObject["UniqueId"].GetString(),
                                                                    groupObject["Title"].GetString(),
                                                                    groupObject["Subtitle"].GetString(),
                                                                    groupObject["ImagePath"].GetString());

                        foreach (JsonValue itemValue in groupObject["Items"].GetArray())
                        {
                            JsonObject itemObject = itemValue.GetObject();
                            group.Items.Add(new SampleDataItem(itemObject["UniqueId"].GetString(),
                                                               itemObject["Title"].GetString(),
                                                               itemObject["Subtitle"].GetString(),
                                                               itemObject["ImagePath"].GetString(),
                                                               itemObject["Content"].GetString()));
                        }
                        this.Groups.Add(group);
                    }
                    break;
                }
                catch (Exception exp)
                {
                    Debug.WriteLine(exp.InnerException);
                }
            }
        }