I'm writing a program that makes remote desktop connection with signalr. I keep sending screenshots (in the .net client) for it. But when I reconnect to the server after a while, I get error: Connection started reconnecting before invocation result was received.
public void ImageMain()
{
var querstring = new Dictionary<string, string>();
querstring.Add("userid", "sessionlocal");
var hubConnectionMouse = new HubConnection("http://localhost:8089/", querstring);
Program p = new Program();
IHubProxy myHubProxyMouse = hubConnectionMouse.CreateHubProxy("MyHub");
string a = "";
try
{
hubConnectionMouse.Start().Wait();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
byte[] ekran;
while (true)
{
ekran = null;
ekran = EkranGoruntusu();
if (ekran.Length < 80000)
{
try
{
myHubProxy.Invoke("addMessage", "sessionlocal", ekran).ContinueWith(task =>
{
if (task.IsFaulted)
{
Console.WriteLine("!!! image gönderilirken hata olıştu:{0} \n",
task.Exception.GetBaseException() + "tekrar bağlanılıyor....");
}
else
{
Console.WriteLine("Add messgae" + " gonderilecek ekran boyutu " + ekran.Length);
Console.WriteLine("hub durumu" + hubConnection.State);
}
}).Wait();
}
catch (Exception exception)
{
Console.WriteLine("bağlantı hatas tekrar bağlanılıyor" + exception.Message);
Console.ReadKey();
}
}
else
{
Console.WriteLine("gonderilcek goruntü cok büyük");
}
}
Console.ReadLine();
}
Related
If I code a WHOIS server program, say using languages like C# and Java, what functionalities must I supply?
What I understand is, WHOIS servers listen to the port no. 43. When they receive a command "whois", they respond with various information pertaining to the server itself.
So, it's just a normal TCP/IP server that listens to a special port and serves a specific purpose.
Am I correct?
Whois Client:
using System;
using System.Net.Sockets;
using System.IO;
public class Whois
{
static void Main(string[] args)
{
try
{
TcpClient client = new TcpClient();
client.Connect("localHost", 43);
if (args.Length < 1)
{
Console.WriteLine("Provide more than one Args");
}
else if (args.Length == 1)
{
StreamWriter sw = new StreamWriter(client.GetStream());
StreamReader sr = new StreamReader(client.GetStream());
sw.WriteLine(args[0]);
sw.Flush();
Console.WriteLine(args[0] + " is "+ sr.ReadToEnd());
return;
}
else if (args.Length > 1)
{
StreamWriter sw = new StreamWriter(client.GetStream());
StreamReader sr = new StreamReader(client.GetStream());
string str = "";
foreach (string arg in args)
{
str += arg + " ";
}
sw.WriteLine(str);
sw.Flush();
Console.WriteLine(args[0] + " location changed to be " + args[1]);
sw.Close();
return;
}
else Console.WriteLine("Invalid args ");
return;
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
}
Whois Server:
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Collections.Generic;
namespace locationserver
{
public class respond
{
static Dictionary<string, string> SavedLocationa = new Dictionary<String, String>();
static void Main(string[] args)
{
runServer();
}
static void runServer()
{
TcpListener listener;
Socket connection;
NetworkStream socketStream;
try
{
listener = new TcpListener(IPAddress.Any, 43);
listener.Start();
Console.WriteLine("server started listening");
while (true)
{
connection = listener.AcceptSocket();
socketStream = new NetworkStream(connection);
Console.WriteLine("Connection Received");
doRequest(socketStream);
socketStream.Close();
connection.Close();
}
}
catch (Exception e)
{
Console.WriteLine("Exception:" + e.ToString());
}
}
static void doRequest(NetworkStream socketStream)
{
try
{
StreamWriter sw = new StreamWriter(socketStream);
StreamReader sr = new StreamReader(socketStream);
String line = sr.ReadLine();
Console.WriteLine("Respond Received:" + line);
String[] sections = line.Split(new char[] { ' ' }, 2);
String names, location;
if (line.Contains("-h0"))
{
Console.WriteLine(" Is ok");
}
else if (line.Contains("-h9"))
{
Console.WriteLine("Hey you're progressing");
}
else if (line.Contains("-h1"))
{
Console.WriteLine("We're Done");
}
if (sections.Length < 1)
{
Console.WriteLine("Too little words was inputted");
}
else if (sections.Length == 1)
{
names = sections[0];
if (SavedLocationa.ContainsKey(names))
{
sw.WriteLine(SavedLocationa[names]);
}
else
{
sw.WriteLine("Error no entries found");
}
sw.Flush();
Console.WriteLine("Error no entries found");
}
else if (sections.Length == 2)
{
names = sections[0];
location = sections[1];
if (SavedLocationa.ContainsKey(names))
{
SavedLocationa.Remove(names);
}
else
{
SavedLocationa.Add(names, location);
sw.WriteLine("Update Successful");
}
sw.Flush();
}
}
catch (Exception e)
{
Console.WriteLine("Something went wrong");
Console.WriteLine(e.Message);
}
}
}
}
What functionalities are missing in the server portion of the code?
This is killing me. I'm new to android/Xamarin. I can't find anything on the web that explains what is going on here.
I'm using xamarin forms for my application. I have a page that synchronizes the device with a web service.
The method simply retrieves 100 records at a time from the web service and updates a sqlite table on the device. I randomly get this error. I'm running 5000 records for my test sample.
Here is the button click:
public async void OnSyncCachedData_Clicked(object sender, EventArgs e)
{
activityIndicatorAll.IsRunning = true;
try
{
actIndSyncItems.IsRunning = true;
SyncAllFinished += SynchAllFinishedProcessing;
await Task.Run(async () => await App.ItemsRepo.LoadCacheDataFromCacheAsync(DbPath).ConfigureAwait(false));
}
catch (BAL.Exceptions.NetworkException nex)
{
await DisplayAlert(Messages.TitleError, nex.Message, Messages.MsgOk);
}
catch (Exception ex)
{
await DisplayAlert(Messages.TitleError, string.Format(Messages.MsgAreYouConnectedParm1, ex.Message), Messages.MsgOk);
}
finally
{
EventHandler handler = SyncAllFinished;
if (handler != null)
{
handler(this, new EventArgs());
}
SyncAllFinished -= SynchAllFinishedProcessing;
}
}
the main worker method:
public async Task<bool> LoadCacheDataFromCacheAsync(string dbPath)
{
WebSvcManagers.ItemsManager itemsWebServiceManager = new WebSvcManagers.ItemsManager();
List<Models.WebServiceItems> consumedRecords = new List<Models.WebServiceItems>() { };
int bufferSize = 100;
Log.Debug(TAG, "LoadCacheDataFromCacheAsync starting");
try
{
{
int lastID = 0;
IEnumerable<Models.WebServiceItems> remoteRecords = await BAL.DataAccessHelper.GetItemsFromGPCacheAsync(App.Login, lastID, bufferSize, itemsWebServiceManager).ConfigureAwait(false);
while (remoteRecords.Count() != 0)
{
foreach (Models.WebServiceItems remoteItem in remoteRecords)
{
// DbActionTypes dbAction = (DbActionTypes)remoteItem.DbAction;
Models.Items itemRecord = new Models.Items() { ItemNumber = remoteItem.ItemNumber.ToUpper().Trim(), Description = remoteItem.Description.Trim() };
Log.Debug(TAG, "Processing {0}", remoteItem.ItemNumber.Trim());
bool success = await AddRecordAsync(itemRecord).ConfigureAwait(false);
if (success)
consumedRecords.Add(remoteItem);
}
lastID = remoteRecords.Max(r => r.RecordID) + 1;
remoteRecords = await BAL.DataAccessHelper.GetItemsFromGPCacheAsync(App.Login, lastID, bufferSize, itemsWebServiceManager).ConfigureAwait(false);
}
}
// await UpdateConsumedRecords(consumedRecords).ConfigureAwait(false);
return true;
}
catch (Exception ex)
{
this.StatusMessage = ex.Message;
Log.Debug(TAG, "Error Catch: {0}", StatusMessage);
return false;
}
finally
{
itemsWebServiceManager = null;
HandleSyncFinished(this, new EventArgs());
SyncAllFinished -= HandleSyncFinished;
}
}
My simple webservice manager:
public static async Task<IEnumerable<Models.WebServiceItems>> GetItemsFromGPCacheAsync(Models.Login login, int offset, int bufferCount, WebSvcManagers.ItemsManager manager)
{
try
{
return await manager.GetCacheRecordsAsync(login, offset, bufferCount).ConfigureAwait(false);
}
catch (Exception)
{
throw;
}
}
And the code for the interaction with the web service:
const int bufferSize = 100;
public async Task<IEnumerable<Models.WebServiceItems>> GetCacheRecordsAsync(Models.Login login, int offSet, int bufferCount)
{
string deviceID = App.ConfigSettings.DeviceID.ToString("D");
try
{
///* Testing start */
//return await DataStore(bufferCount, offSet).ConfigureAwait(false);
///* Testing end */
if (!App.IsConnected)
throw new BAL.Exceptions.NetworkException(Messages.ExceptionNetworkConnection);
string user = login.UserName;
string password = login.Password;
HttpClient client = HttpClientExtensions.CreateHttpClient(user, password);
try
{
List<Models.WebServiceItems> items = new List<Models.WebServiceItems>() { };
int lastID = offSet;
int i = 0;
string uri = string.Format("{0}", string.Format(Messages.WebRequestItemsCacheParms3, deviceID, lastID, Math.Min(bufferCount, bufferSize)));
Log.Debug(TAG, string.Format("Webservice {0}", uri));
string response = await client.GetStringAsync(uri).ConfigureAwait(false);
while (i < bufferCount && response != null && response != "[]")
{
while (response != null && response != "[]")
{
dynamic array = JsonConvert.DeserializeObject(response);
foreach (var item in array)
{
i++;
items.Add(new Models.WebServiceItems()
{
ItemNumber = item["ITEMNMBR"].Value.Trim(),
Description = item["ITEMDESC"].Value.Trim(),
DbAction = (int)(item["DbAction"].Value),
RecordID = (int)(item["DEX_ROW_ID"].Value),
});
lastID = (int)(item["DEX_ROW_ID"].Value);
Log.Debug(TAG, string.Format("Webservice {0}", item["ITEMNMBR"].Value.Trim()));
}
if (i < Math.Min(bufferCount, bufferSize))
{
uri = string.Format("{0}", string.Format(Messages.WebRequestItemsCacheParms3, deviceID, lastID + 1, Math.Min(bufferCount, bufferSize)));
Log.Debug(TAG, string.Format("Webservice {0}", uri));
response = await client.GetStringAsync(uri).ConfigureAwait(false);
}
else
break;
}
}
Log.Debug(TAG, string.Format("Webservice return {0} items", items.Count()));
return items;
}
catch (Exception ex)
{
Log.Debug(TAG, "Error Catch: {0}", ex.Message);
throw ex;
}
}
catch (System.Net.Http.HttpRequestException nex)
{
throw new Exception(string.Format(Messages.ExceptionWebServiceLoginParm1, nex.Message));
}
catch (Exception)
{
throw;
}
}
I've had assistance from a Xamarin instructor and we thought we got it, (because this is random), but it clearly is not swatted. I've been hitting my head up against a wall for over 3 weeks on this. It smells like a memory leak, but I have no idea how to find it with such a generic error message that doesn't appear on web searches.
Somebody out there with some major brains, Please help!
Error:
08-03 12:41:11.281 D/X:ItemsRepositiory(16980): UpdateRecordAsync 65702-40710
08-03 12:41:11.306 D/X:ItemsManager(16980): Webservice DeleteCacheRecordAsync 20497
08-03 12:41:11.406 D/X:ItemsManager(16980): Webservice api/InventoryItems?DeviceID=7c5bb45d-2ea0-45b9-ae50-92f2e25a2983&OffSet=20498&Max=100&cached=true
Thread finished: <Thread Pool> #7 08-03 12:41:11.521 E/art (16980): Nested signal detected - original signal being reported The thread 'Unknown' (0x7) has exited with code 0 (0x0).
This might be a problem with the VS Android Emulator. As we have shown in tests, this is not reproducible on the Google Android Emulators, nor on Xamarin Android Player, nor on a physical Android device.
I'm using C# and Windows Phone 8.1 as Universal.
I Have an issue with BackgroundDownloader. when I start a downloader, it gave me an exception:
Downloading http://localhost/MySong.mp3 to MySong.mp3 with Default priority, a95c00db-738d-4e22-a456-dc30d49b0a3b
A first chance exception of type 'System.IO.FileNotFoundException' occurred in mscorlib.dll
Exception: The system cannot find the file specified. (Exception from HRESULT: 0x80070002)
here is my code:
private void downladButton_Tapped(object sender, TappedRoutedEventArgs e)
{
PumpUrl(txtUrl.Text);
}
async void PumpUrl(string url)
{
if (!string.IsNullOrEmpty(url) && CheckUrl(url))
StartDownloadMethod(url);
else
await new MessageDialog("Looks like URL is invalid.\r\nPlease check your URL and try again"").ShowAsync();
}
public bool CheckUrl(string URL)
{
Uri source;
if (Uri.TryCreate(URL, UriKind.RelativeOrAbsolute, out source))
return true;
else
return false;
}
public void StartDownloadMethod(string url, string fileName = null)
{
StartDownload(url, BackgroundTransferPriority.Default, false, fileName);
}
private async void StartDownload(string url, BackgroundTransferPriority priority, bool requestUnconstrainedDownload, string fileName = null)
{
Uri source;
if (!Uri.TryCreate(url.Trim(), UriKind.RelativeOrAbsolute, out source))
{
Debug.WriteLine("Invalid URI.");
return;
}
string destination = null;
if (string.IsNullOrEmpty(fileName))
try
{
destination = System.IO.Path.GetFileName(Uri.UnescapeDataString(url)).Trim();
}
catch { }
else
destination = Uri.UnescapeDataString(fileName).Trim();
if (string.IsNullOrWhiteSpace(destination))
{
Debug.WriteLine("A local file name is required.");
return;
}
StorageFile destinationFile = null;
try
{
if (vars.localType == LocalType.SDCard)
destinationFile = await KnownFolders.RemovableDevices.CreateFileAsync(
"Downloads\\Test App\\" + destination, CreationCollisionOption.GenerateUniqueName);
else
destinationFile = await KnownFolders.MusicLibrary.CreateFileAsync(
"Test App\\" + destination, CreationCollisionOption.GenerateUniqueName);
}
catch (FileNotFoundException ex)
{
Debug.WriteLine("Error while creating file: " + ex.Message);
return;
}
catch (Exception ex) { Debug.WriteLine("Error while creating file: " + ex.Message); }
if (destinationFile == null)
return;
BackgroundDownloader downloader = new BackgroundDownloader();
DownloadOperation download = downloader.CreateDownload(source, destinationFile);
Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "Downloading {0} to {1} with {2} priority, {3}",
source.AbsoluteUri, destinationFile.Name, priority, download.Guid));
download.Priority = priority;
Add(url, destination, download);
if (!requestUnconstrainedDownload)
{
// Attach progress and completion handlers.
await HandleDownloadAsync(download, true);
return;
}
List<DownloadOperation> requestOperations = new List<DownloadOperation>();
requestOperations.Add(download);
UnconstrainedTransferRequestResult result;
try
{
result = await BackgroundDownloader.RequestUnconstrainedDownloadsAsync(requestOperations);
}
catch (NotImplementedException)
{
Debug.WriteLine(
"BackgroundDownloader.RequestUnconstrainedDownloadsAsync is not supported in Windows Phone.");
return;
}
Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "Request for unconstrained downloads has been {0}",
(result.IsUnconstrained ? "granted" : "denied")));
await HandleDownloadAsync(download, true);
}
private async Task HandleDownloadAsync(DownloadOperation download, bool start)
{
try
{
Debug.WriteLine("Running: " + download.Guid);
bool bb = false;
foreach (DownloadOperation item in DownloadDB.activeDownloads)
{
if (item != null && item.Guid == download.Guid)
{
bb = true;
break;
}
}
if (!bb)
DownloadDB.activeDownloads.Add(download);
Progress<DownloadOperation> progressCallback = new Progress<DownloadOperation>(DownloadProgress);
CancellationTokenSource cts = new CancellationTokenSource();
AppendCancellationTokenSource(download, cts);
if (start)
await download.StartAsync().AsTask(cts.Token, progressCallback);
else
await download.AttachAsync().AsTask(cts.Token, progressCallback);
ResponseInformation response = download.GetResponseInformation();
DownloadDB.RemoveChildByGuid(download.Guid.ToString());
DownloadDB.SaveDB();
Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "Completed: {0}, Status Code: {1}",
download.Guid, response.StatusCode));
}
catch (TaskCanceledException taskCanceled)
{
Debug.WriteLine("TaskCanceledException: " + download.Guid + "\t" + taskCanceled.Message);
DownloadDB.RemoveChildByGuid(download.Guid.ToString());
}
catch (Exception ex)
{
Debug.WriteLine("Exception: " + ex.Message);
}
finally
{
DownloadDB.RemoveChildByGuid(download.Guid.ToString());
DownloadDB.activeDownloads.Remove(download);
}
}
I used my code in other application 3 month ago and it works fine but in this application dosent work. Where I wrong?
Thanks
I'm having an issue with a TCPListener. I have created this code below and it works with a test application, but I can't get it to receive the connection from the production box. In the image below you can see .44 is continuously attempting to connect, but as seen in the Console window output, no connection is ever received beyond the Listening Started.
What am I overlooking?
public class TCPServer
{
#region Privates
private ILog log;
private readonly string _connectionString = "";
private readonly List<AgentState> _lAgentState;
private readonly DateTime _lastUpdatedRecord = new DateTime();
private readonly TcpClient _tcpClient;
private readonly IPEndPoint _serverEndPoint;
private int _messageNumber = 2;
private TcpListener _tcpListener;
private Thread _listenThread;
#endregion
public IEXHermes()
{
var methodName = new System.Diagnostics.StackTrace().GetFrame(0).GetMethod().Name;
try
{
log = LogManager.GetLogger("Logger");
log.Info("Class Starting");
_connectionString = Properties.Settings.Default.HN_ConnectionString;
_lAgentState = getInitialState();
_lastUpdatedRecord = _lAgentState.Max(w => w.actionLocalTime);
Int32 iexPort = Int32.Parse(Properties.Settings.Default.IEX_Port);
_tcpListener = new TcpListener(IPAddress.Any, iexPort);
log.Debug("Server Open on Server: " + IPAddress.Any);
log.Debug("Server Open on Port: " + iexPort);
_listenThread = new Thread(listenForClients);
_listenThread.Start();
}
catch (Exception ex)
{
log.FatalFormat("{0} - {1} \n {2}", methodName, ex.Message, ex.StackTrace);
}
}
private void listenForClients()
{
var methodName = new System.Diagnostics.StackTrace().GetFrame(0).GetMethod().Name;
log.Debug(methodName + " Starting");
try
{
log.Debug(methodName + " - Listening Started");
_tcpListener.Start();
while (true)
{
try
{
var client = _tcpListener.AcceptSocket();
var clientThread = new Thread(handleClientComm);
clientThread.Start(client);
}
catch (Exception ex)
{
log.FatalFormat("{0} - {1} \n {2}", methodName, ex.Message, ex.StackTrace);
}
}
} catch (Exception ex)
{
log.FatalFormat("{0} - {1} \n {2}", methodName, ex.Message, ex.StackTrace);
}
log.Debug(methodName + ": Listener Closer");
}
private void handleClientComm(object client)
{
var methodName = new System.Diagnostics.StackTrace().GetFrame(0).GetMethod().Name;
var tcpClient = (TcpClient)client;
log.Debug(methodName + ": New Connection Established");
try
{
var clientStream = tcpClient.GetStream();
var message = new byte[4096];
while (true)
{
var bytesRead = 0;
try
{
bytesRead = clientStream.Read(message, 0, 4096);
}
catch
{
break;
}
if (bytesRead == 0)
{
break;
}
var encoder = new ASCIIEncoding();
var a = encoder.GetString(message, 0, bytesRead);
Console.WriteLine("Recieved: " + a.ToUpper());
if (a.ToUpper().Contains("INIT"))
{
a = sessionInitialize();
}
tcpClient.Client.Send(Encoding.UTF8.GetBytes(a));
Console.WriteLine("Sent: " + a);
}
}
catch (Exception ex)
{
log.FatalFormat("{0} - {1} \n {2}", methodName, ex.Message, ex.StackTrace);
}
finally
{
tcpClient.Close();
}
}
}
maybe try to replace IPAddress.Any by the real IP at least for testing purpose, just to be sure...
The problem - I can't get this functions working. I see in LogCat that socket is connected to c# server, but I don't see received data. What I'm doing wrong?
Here is c# function with MessageBoxes for checking:
private void receiveConnection(){
Socket myHandler = null;
bool isConnected = false;
while (true)
{
if (!isConnected)
{
myHandler = wSocket.Accept();
isConnected = true;
MessageBox.Show("We have client!");
}
if (sendDataToAndroid)
{
try
{
sendDataToAndroid = false;
NetworkStream stream = new NetworkStream(myHandler);
StreamWriter sw = new StreamWriter(stream);
string myMsg = "";
myMsg += temp_F.Length + " ";
temp_F[0] = 3.151F;
temp_F[1] = 1.415F;
temp_F[2] = 5.572F;
temp_F[3] = 6.320F;
for (int i = 0; i < temp_F.Length; i++)
{
myMsg += temp_F[i] + " ";
}
byte[] msg = Encoding.ASCII.GetBytes(myMsg);
MessageBox.Show("Data to send: " + myMsg);
try
{
myHandler.Send(msg);
MessageBox.Show("Data has been sent!");
}
catch (Exception e) {
MessageBox.Show("Error while sending data!");
}
}
catch (Exception e)
{
isConnected = false;
myHandler.Close();
myHandler = null;
MessageBox.Show("Error while sending data...");
}
}
}
}
And here is Android function which is always trying to receive data:
public class SendThread implements Runnable {
public void run()
{
Socket socket = null;
BufferedReader in = null;
while (true)
{
// Loop until connected to server
while (socket == null){
try{
socket = new Socket ("192.168.137.1", 808);
}
catch (Exception e) {
socket = null;
}
}
// Get from the server
try {
Log.d("Connection: ", "connected");
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
Log.d("Socket:", line);
NumberFormat nf = new DecimalFormat ("990,0");
String[] tokens = line.split(" ");
int currTempSize = Integer.parseInt(tokens[0]);
currentTemp = new double[currTempSize];
for (int i = 0; i < currTempSize; i++)
currentTemp[i] = (Double) nf.parse(tokens[i+1]);
//Toast.makeText(getApplicationContext(), "Received data:", duration)
for (int i = 0; i < currTempSize; i++){
Log.d("Converted data: currentTemp["+i+"] = ", currentTemp[i]+"");
}
}
}
catch (Exception e) {
socket = null;
in = null;
Log.d("Connection: ", "lost.");
}
}
}
}
Your Java code reads a line at a time but you never sent a line terminator from C#.
You could append one to myMsg manually, or you could use the sw.WriteLine() method on your StreamWriter (which don't otherwise seem to be using). After calling sw.WriteLine() you will probably have to call sw.Flush().