We Keep Coding

How to convert a script(Capture Packets and save it to log file) into Window Service?

I want to write a window service for keep capturing the network traffic and save the packets info into a log file, but I can't start it.
"Error 1064: An exception occurred in the service when handling the control request."
References:
Capturing And Parsing Packets
Save Output to Log
Create Window Service
Here's the code for Windows Service(failed):
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
using CapturingAndParsingPackets;
using PacketDotNet;
using SharpPcap;
namespace CaptureService
{
public partial class Service1 : ServiceBase
{
private static bool _stopCapturing;
string path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);//Get the desktop path
string filename = DateTime.Now.ToString("yyyy-MM-dd--HH-mm-ss");//Use date to name the file
public Service1()
{
InitializeComponent();
var devices = CaptureDeviceList.Instance; //Get the local devices
if (devices.Count < 1)
{
OnStop();
return;
}
}
protected override void OnStart(string[] args)
{
var devices = CaptureDeviceList.Instance; //Get the local devices
//set output type
var defaultOutputType = StringOutputType.Normal;
var outputTypeValues = Enum.GetValues(typeof(StringOutputType));
StringOutputType selectedOutputType = defaultOutputType;
int userSelectedOutputType;
userSelectedOutputType = 3;
selectedOutputType = (StringOutputType)userSelectedOutputType;
//read local device
var device = devices[3];
//read packets
var readTimeoutMilliseconds = 1000;
device.Open(DeviceModes.Promiscuous, readTimeoutMilliseconds);
//set filter
string filter = "host 192.168.0.212";
device.Filter = filter;
PacketCapture e;
var status = device.GetNextPacket(out e);
var rawCapture = e.GetPacket();
// use PacketDotNet to parse this packet and print out
// its high level information
var p = Packet.ParsePacket(rawCapture.GetLinkLayers(), rawCapture.Data);
// Create a log file to desktop and write the log into the log file
using (StreamWriter w = File.AppendText(path + "\\" + filename + ".log"))
{
Log(p.ToString(selectedOutputType) + p.PrintHex(), w);
}
device.Close();
}
public static void Log(string logMessage, TextWriter txtWriter)
{
try
{
txtWriter.Write("\r\nLog Entry : ");
txtWriter.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),
DateTime.Now.ToLongDateString());
txtWriter.WriteLine();
txtWriter.WriteLine(logMessage);
txtWriter.WriteLine("============================================================================================================");
}
catch (Exception)
{
}
}
protected override void OnStop()
{
using (StreamWriter w = File.AppendText(path + "\\" + filename + ".log"))
{
Log("Service is stopped at " + DateTime.Now, w);
}
}
}
}
And Here is the script for just running it in VS(works fine):
using System;
using PacketDotNet;
using SharpPcap;
using System.IO;
using System.Reflection;
using log4net;
using log4net.Config;
namespace CapturingAndParsingPackets
{
class MainClass
{
// used to stop the capture loop
private static bool _stopCapturing;
public static void Main(string[] args)
{
// Print SharpPcap version
var ver = SharpPcap.Pcap.SharpPcapVersion;
Console.WriteLine("PacketDotNet example using SharpPcap {0}", ver);
// Retrieve the device list
var devices = CaptureDeviceList.Instance;
// If no devices were found print an error
if (devices.Count < 1)
{
Console.WriteLine("No devices were found on this machine");
return;
}
Console.WriteLine();
Console.WriteLine("The following devices are available on this machine:");
Console.WriteLine("----------------------------------------------------");
Console.WriteLine();
var i = 0;
// Print out the devices
foreach (var dev in devices)
{
/* Description */
Console.WriteLine("{0}) {1} {2}", i, dev.Name, dev.Description);
i++;
}
Console.WriteLine();
Console.Write("-- Please choose a device to capture: ");
Console.WriteLine();
Console.WriteLine("Output Verbosity Options");
Console.WriteLine("----------------------------------------------------");
Console.WriteLine();
var defaultOutputType = StringOutputType.Normal;
var outputTypeValues = Enum.GetValues(typeof(StringOutputType));
foreach (StringOutputType outputType in outputTypeValues)
{
Console.Write("{0} - {1}", (int)outputType, outputType);
if (outputType == defaultOutputType)
{
Console.Write(" (default)");
}
Console.WriteLine("");
}
Console.WriteLine();
Console.Write("-- Please choose a verbosity (or press enter for the default): ");
StringOutputType selectedOutputType = defaultOutputType;
int userSelectedOutputType;
//Fixed
userSelectedOutputType = 3;
selectedOutputType = (StringOutputType)userSelectedOutputType;
// Register a cancel handler that lets us break out of our capture loop
Console.CancelKeyPress += HandleCancelKeyPress;
//Fixed
var device = devices[3];
// Open the device for capturing
var readTimeoutMilliseconds = 1000;
device.Open(DeviceModes.Promiscuous, readTimeoutMilliseconds);
//filter host 192.168.0.212
//or you can set it to "filter = 'ip'; " for default
string filter = "host 192.168.0.212";
device.Filter = filter;
Console.WriteLine();
Console.WriteLine("-- Listening on {0}, hit 'ctrl-c' to stop...",
device.Name);
while (_stopCapturing == false)
{
PacketCapture e;
var status = device.GetNextPacket(out e);
// null packets can be returned in the case where
// the GetNextRawPacket() timed out, we should just attempt
// to retrieve another packet by looping the while() again
if (status != GetPacketStatus.PacketRead)
{
// go back to the start of the while()
continue;
}
var rawCapture = e.GetPacket();
// use PacketDotNet to parse this packet and print out
// its high level information
var p = Packet.ParsePacket(rawCapture.GetLinkLayers(), rawCapture.Data);
Console.WriteLine(p.ToString(selectedOutputType) + p.PrintHex());
Console.WriteLine("============================================================================================================");
using (StreamWriter w = File.AppendText("networkTraffic.log"))
{
Log(p.ToString(selectedOutputType), w);
Log(p.PrintHex(), w);
}
}
Console.WriteLine("-- Capture stopped");
// Print out the device statistics
Console.WriteLine(device.Statistics.ToString());
// Close the pcap device
device.Close();
}
static void Log(string logMessage, TextWriter txtWriter)
{
try
{
txtWriter.Write("\r\nLog Entry : ");
txtWriter.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),
DateTime.Now.ToLongDateString());
txtWriter.WriteLine();
txtWriter.WriteLine(logMessage);
txtWriter.WriteLine("============================================================================================================");
}
catch (Exception)
{
}
}
static void HandleCancelKeyPress(object sender, ConsoleCancelEventArgs e)
{
Console.WriteLine("-- Stopping capture");
_stopCapturing = true;
// tell the handler that we are taking care of shutting down, don't
// shut us down after we return because we need to do just a little
// bit more processing to close the open capture device etc
e.Cancel = true;
}
}
}
The error that shows in Event Viewer(1064):
Application: CaptureTrafficService.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileNotFoundException
at CaptureTrafficService.Service1.OnStart(System.String[])
at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(System.Object)
at System.ServiceProcess.ServiceBase.Run(System.ServiceProcess.ServiceBase[])
at CaptureTrafficService.Program.Main()
Service cannot be started. System.IO.FileNotFoundException: Could not load file or assembly 'netstandard, Version=2.1.0.0, Culture=neutral, PublicKeyToken=cc7b1xxxxxxxxxxx' or one of its dependencies. The system cannot find the file specified.
File name: 'netstandard, Version=2.1.0.0, Culture=neutral, PublicKeyToken=cc7b1xxxxxxxxxxx'
at CaptureTrafficService.Service1.OnStart(String[] args)
at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)
After I remove the while loop in OnStart method, It shows up another error(1053):
Application: CaptureTrafficService.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileNotFoundException
Exception Info: System.IO.FileNotFoundException
at CaptureService.Service1..ctor()
at CaptureService.Program.Main()

The answer by #Sam1916 might lessen the frustration of FileNotFoundException.
The "System.IO.FileNotFoundException" caught my attention - but missing info on what files.
As Windows services run in "their own context" the files referenced (Through "using") might not exists in a readable directory, hench "FileNotFoundException"
Is the logfile placed in a directory where your service credentials are allowed to write?

There are too many unnecessary references that may affect each other in the solution so that it will return a lot of errors & warnings when building it. Just add them one by one if it is necessary, rebuild it when you added a new reference(for checking the compatibility) and not just copying all of them to the solution.
Too many unnecessary references(Before)
Just add the references you need(After)
Here's the code that works with windows service:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
using System.Timers;
using SharpPcap;
using PacketDotNet;
namespace Capture
{
public partial class Capture : ServiceBase
{
Timer timer = new Timer();
public Capture()
{
InitializeComponent();
}
protected override void OnStart(string[] args)
{
Log("Service started at " + DateTime.Now);
timer.Elapsed += new ElapsedEventHandler(OnElapsedTime);
//timer.Interval = 5000;
timer.Enabled = true;
}
protected override void OnStop()
{
Log("Service is stopped at " + DateTime.Now);
}
private void OnElapsedTime(object source, ElapsedEventArgs e)
{
var devices = CaptureDeviceList.Instance;
//set output type
var defaultOutputType = StringOutputType.Normal;
StringOutputType selectedOutputType = defaultOutputType;
int userSelectedOutputType;
userSelectedOutputType = ? ;//? = 0-3
selectedOutputType = (StringOutputType)userSelectedOutputType;
//read local device
var device = devices[?];//? is mean num 0-4 or more(depends on your device)
//read packets
var readTimeoutMilliseconds = 1000;
device.Open(DeviceModes.Promiscuous, readTimeoutMilliseconds);
PacketCapture d;
var status = device.GetNextPacket(out d);
var rawCapture = d.GetPacket();
var p = Packet.ParsePacket(rawCapture.LinkLayerType, rawCapture.Data);
Log(p.ToString(selectedOutputType) +p.PrintHex());//write to log file
device.Close();
}
public static void Log(string logMessage)
{
string path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);+ "\\Logs" ;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
string filepath =Environment.GetFolderPath(Environment.SpecialFolder.Desktop); + "\\Logs\\ServiceLog_" +
DateTime.Now.Date.ToShortDateString().Replace('/','_') + ".log";
using (StreamWriter sw = File.AppendText(filepath))
{
sw.WriteLine(logMessage);
sw.WriteLine("============================================================================================================");
}
}
}
}

Telegram Flood prevention

There was such a problem: I ran the program many times and now it throws the following error FloodException: Flood prevention. Telegram now requires your program to do requests again only after 73611 seconds have passed (TimeToWait property). If you think the culprit of this problem may lie in TLSharp's implementation, open a Github issue please.
I attach the code below:
using System;
using System.Text;
using System.Windows.Forms;
using TeleSharp.TL;
using TeleSharp.TL.Messages;
using TLSharp.Core;
namespace tgBM
{
public partial class Form1: Form
{
string phone;
string code;
int n = 1;
StringBuilder sb = new StringBuilder ();
TelegramClient client = new TelegramClient (2646156, "08ec188e0bdee432e568120348f5f13a"); // create a client with parameters
public Form1 ()
{
InitializeComponent();
}
string str = "";
public async void authAsync()
{
var dialogs = (TLDialogs) await client.GetUserDialogsAsync();
foreach (var element in dialogs.Chats)
{
TLChat chat = element as TLChat;
if (element is TLChannel)
{
var offset = 0;
TLChannel channel = element as TLChannel;
if (channel.Title == "TOPLES")
{
TLChannel ch = element as TLChannel;
TLInputPeerChannel inputPeer = new TLInputPeerChannel() {ChannelId = ch.Id, AccessHash = (long) ch.AccessHash};
while (n! = 11)
{
try
{
TLChannelMessages res = await client.SendRequestAsync <TLChannelMessages>
(new TLRequestGetHistory() {Peer = inputPeer, Limit = 20, AddOffset = offset, OffsetId = 0});
var msgs = res.Messages;
if (res.Count> offset)
{
offset + = msgs.Count;
foreach (TLAbsMessage msg in msgs)
{
if (msg is TLMessage)
{
TLMessage message = msg as TLMessage;
str + = n.ToString () + "\ t" + message.Id + "\ t" + message.FromId + "\ t" + message.Message + Environment.NewLine;
}
if (msg is TLMessageService)
continue;
n ++;
}
}
else
break;
}
catch (Exception ex)
{
MessageBox.Show (ex.Message);
break;
}
}
}
}
textBox3.Text = str;
}
}
private async void button1_Click (object sender, EventArgs e)
{
phone = textBox1.Text;
await client.ConnectAsync (); // make a connection
var hash = await client.SendCodeRequestAsync(phone);
}
private async void button2_Click (object sender, EventArgs e)
{
code = textBox2.Text;
var user = await client.MakeAuthAsync(phone, await client.SendCodeRequestAsync(phone), code);
authAsync();
}
}
}

In a comment, you said are in a testing phase.
In this case, you should read https://core.telegram.org/api/auth#test-accounts
According to this page, there are 3 ways to perform tests while limiting the risk for FLOOD_WAIT errors:
Connect to the Test servers instead of the Production servers (seems not possible with TLSharp)
Use Test accounts with phone numbers 99966XYYYY (only available on Test servers)
Connect as a user with the phone number you use to create the API ID/Hash
I can do all that with WTelegramClient (TLSharp is no longer maintained and cannot connect to Telegram servers anymore)

Continuous Async Ping inside a Windows Service

I need to monitor a list of hosts continuously. After N seconds, i need to check the list again. So, I tried to use the async ping inside a Windows Service.
I tried to follow tips from other posts related to the topic, but always my service stops shortly after starting it.
There are a problem with await in "OnElapsedTime" function.
Any one have an idea what is wrong? Bellow my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;
using System.Timers;
using System.Net.NetworkInformation;
namespace PingAsyncService
{
public partial class HyBrazil_Ping : ServiceBase
{
Timer timer = new Timer();
List<string> IPList = new List<string>(); //List of IPs
public HyBrazil_Ping()
{
IPList.Add("192.168.0.1");
IPList.Add("192.168.0.254");
InitializeComponent();
}
protected override void OnStart(string[] args)
{
WriteToFile("Service is started at " + DateTime.Now);
timer.Elapsed += new ElapsedEventHandler(OnElapsedTime);
timer.Interval = 5000; //number in miliseconds
timer.Enabled = true;
}
protected override void OnStop()
{
WriteToFile("Service is stopped at " + DateTime.Now);
}
private async void OnElapsedTime(object source, ElapsedEventArgs e)
{
//WriteToFile("Service is recall at " + DateTime.Now);
var ResultList = await PingAsync();
foreach(PingReply reply in ResultList)
{
WriteToFile(reply.Address.ToString() + ";" + reply.Status.ToString());
}
}
private async Task<PingReply> PingAndProcessAsync(Ping pingSender, string ip)
{
var result = await pingSender.SendPingAsync(ip, 2000);
return result;
}
private async Task<List<PingReply>> PingAsync()
{
Ping pingSender = new Ping();
var tasks = IPList.Select(ip => PingAndProcessAsync(pingSender, ip));
var results = await Task.WhenAll(tasks);
return results.ToList();
}
public void WriteToFile(string Message)
{
string path = AppDomain.CurrentDomain.BaseDirectory + "\\Logs";
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
string filepath = AppDomain.CurrentDomain.BaseDirectory + "\\Logs\\ServiceLog_" + DateTime.Now.Date.ToShortDateString().Replace('/', '_') + ".txt";
if (!File.Exists(filepath))
{
// Create a file to write to.
using (StreamWriter sw = File.CreateText(filepath))
{
sw.WriteLine(Message);
}
}
else
{
using (StreamWriter sw = File.AppendText(filepath))
{
sw.WriteLine(Message);
}
}
}
}
}
Thanks a lot!

In one of the comments you mentioned the error message as
"An asynchronous call is already in progress. It must be completed or canceled before you can call this method."
Chances are, the Ping object does not let simultaneous asynchronous calls.
Using a new Ping object everytime, on each call, might help as below.
private async Task<List<PingReply>> PingAsync()
{
// Ping pingSender = new Ping();
var tasks = IPList.Select(ip =>
{
using (var p= new Ping())
{
return PingAndProcessAsync(p, ip);
}
});
var results = await Task.WhenAll(tasks);
return results.ToList();
}

How to make webclient download file again if failed?

I'm trying to download a list of links of images to my server (Up to 40 links) using foreach.
In my case sometimes the link exists but I don't know why it's going to catch and cancel the download of the next link. Maybe it needs to wait for a little? because when I debug the app I see that the link was the application skipped and went to catch was available but sometimes it's open after few seconds in my browser so the response time from the server I trying to download sometimes need more time to load and open the link.
string newPath = "~/data/" + model.PostID + "/" + name + "/";
//test1 is a list of links
foreach (var item1 in test1)
{
HttpWebRequest request = WebRequest.Create(item1) as HttpWebRequest; request.Method = "HEAD";
try
{
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
var webClient = new WebClient();
string path = newPath + i + ".jpg";
webClient.DownloadFileAsync(new Uri(item1), Server.MapPath(path));
string newlinks = "https://example.com/data/" + chapter.PostID + "/" + name + "/" + i + ".jpg";
allimages = allimages + newlinks + ',';
response.Close();
i++;
}
}
catch
{
break;
}
}
Now my main goal is to fix this issue but as I saw in debugging:
The Images Links I'm trying to download exists
Sometimes Need More Time to response
So How I can fix this ? when download cancel and a link exists, what I should do?

you can use this example:
class WebClientUtility : WebClient
{
public int Timeout { get; set; }
public WebClientUtility() : this(60000) { }
public WebClientUtility(int timeout)
{
this.Timeout = timeout;
}
protected override WebRequest GetWebRequest(Uri address)
{
var request = base.GetWebRequest(address);
if (request != null)
{
request.Timeout = Timeout;
}
return request;
}
}
//
public class DownloadHelper : IDisposable
{
private WebClientUtility _webClient;
private string _downloadUrl;
private string _savePath;
private int _retryCount;
public DownloadHelper(string downloadUrl, string savePath)
{
_savePath = savePath;
_downloadUrl = downloadUrl;
_webClient = new WebClientUtility();
_webClient.DownloadFileCompleted += ClientOnDownloadFileCompleted;
}
public void StartDownload()
{
_webClient.DownloadFileAsync(new Uri(_downloadUrl), _savePath);
}
private void ClientOnDownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
{
if (e.Error != null)
{
_retryCount++;
if (_retryCount < 3)
{
_webClient.DownloadFileAsync(new Uri(_downloadUrl), _savePath);
}
else
{
Console.WriteLine(e.Error.Message);
}
}
else
{
_retryCount = 0;
Console.WriteLine($"successfully download: # {_downloadUrl} to # {_savePath}");
}
}
public void Dispose()
{
_webClient.Dispose();
}
}
//
class Program
{
private static void Main(string[] args)
{
for (int i = 0; i < 100; i++)
{
var downloadUrl = $#"https://example.com/mag-{i}.pdf";
var savePath = $#"D:\DownloadFile\FileName{i}.pdf";
DownloadHelper downloadHelper = new DownloadHelper(downloadUrl, savePath);
downloadHelper.StartDownload();
}
Console.ReadLine();
}
}
to fix timeout problem you can create a derived class and set the timeout property of the base WebRequest class and
for retry you can use the DownloadFileCompleted event of the WebClient and implement your retry pattern there

You're using the async version of 'DownloadFileAsync'. However you're not awaiting the call, that leaves a mess with unpredicted behaviour.
Make your method async and then use this:
await webClient.DownloadFileAsync(new Uri(item1), Server.MapPath(path));

This Solved my case:
await Task.Run(() =>
{
webClient.DownloadFileAsync(new Uri(item1), Server.MapPath(path));
});

Function works when called synchronously, but does not work when called asynchronously

It is my first post on StackOverflow forum so please to be lenient. I have a problem with function which works called synchronously, but doesnot works called asynchronously.
Below You will find function called synchronously:
private void issueInvoices(List<int> lista)
{
foreach (int knh_id in lista)
{
Invoice fs = new Invoice();
fs.FKS_AKCYZA = false;
fs.FKS_CZY_KLON = false;
fs.FKS_DATE = Convert.ToDateTime(MTBDataZapisuDoFK.Text);
fs.NUMBER = knh_id);
}
}
As You can see i passed list to function named issueInvoices list of invoice numbers and in loop i create some invoices.
This function works properly but if i try to call it asynchronously (to display progress bar) my function can not assign to fs.FKS_DATE object dateTime. It looks like static function “Convert.ToDateTime” doesnot work properly. But please take a look on below code where function issueInvoices is called asynchronously…
public delegate void BinaryDelegate(List<int> knh_id);
BinaryDelegate b = new BinaryDelegate(issueInvoices);
IAsyncResult theAsRes = b.BeginInvoke(lista, new AsyncCallback(AddComplete), "Thx U!");
FrmProgressBar fpb=new FrmProgressBar(“Please wait…”);
fpb.Show();
/* below i check how many operation i have to do, if all operations are done, then I close fpb window, program is updating progres bar and in thread make operation issueInvoices*/
while (ilosc_zrobionych != liczbaKontrahentow)
{
fpb.PBStan.Value = (int)((100 * ilosc_zrobionych) / liczbaKontrahentow);
}
fpb.Close();
I put some breakpoints and it looks like program stoping in line, it can conver to datetime, but when i do this synchronously, it works without any errors.
fs.FKS_DATE = Convert.ToDateTime(MTBDataZapisuDoFK.Text);
What could couse this problem and how to resolve it?
Many thanks in advance for reply.
BELOW IS WHOLE CLASS CALLED ASYNCHRONOUSLY:
using System;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Npgsql;
using Castle.ActiveRecord;
using WFR.Model;
using System.Threading;
namespace Faktury_i_Rachunki_2.Forms
{
public partial class FrmEmisjaFakturPotwierdzonych : FrmBaseForm
{
private ArrayList listaSposobowZaplaty;
public List<int> lista;
private int liczbaWygenerowach;
private int liczbaKontrahentow;
private int ilosc_zrobionych;
private FrmProgressBar fpb;
public delegate void BinaryDelegate(List<int> knh_id);
public FrmEmisjaFakturPotwierdzonych()
{
InitializeComponent();
fpb = new FrmProgressBar("Please wait....");
}
private void BtOK_Click(object sender, EventArgs e)
{
BinaryDelegate b = new BinaryDelegate(WyemitujFakture);
lista.Add(12);
lista.Add(13);
lista.Add(17);
lista.Add(1);
liczbaKontrahentow = lista.Count;
if (TBRejestr.Text.Trim() != "")
{
if (liczbaKontrahentow > 0)
{
liczbaWygenerowach = 0;
ilosc_zrobionych = 0;
WyemitujFakture(lista);
IAsyncResult theAsRes = b.BeginInvoke(lista, new AsyncCallback(AddComplete), "THX");
fpb.Show();
while (ilosc_zrobionych != liczbaKontrahentow)
{
fpb.PBStan.Value = (int)((100 * ilosc_zrobionych) / liczbaKontrahentow);
}
fpb.Close();
}
try
{
MessageBox.Show("Wygenerowano " + liczbaWygenerowach.ToString() + " faktur");
}
catch
{
}
}
}
private void WyemitujFakture(List<int> lista)
{
foreach (int knh_id in lista)
{
try
{
if (luk.Count > 0)
{
FakturySprzedazy fs = new FakturySprzedazy();
fs.FKS_AKCYZA = false;
fs.FKS_CZY_KLON = false;
fs.FKS_DATA_DOW_KS = Convert.ToDateTime(MTBDataZapisuDoFK.Text);
fs.FKS_DATA_FAKTURY = Convert.ToDateTime(MTBDataFaktury.Text);
fs.FKS_DATA_SPRZEDAZY = Convert.ToDateTime(MTBDataSprzedazy.Text);
liczbaWygenerowach++;
}
}
catch (Exception ex)
{
MessageBox.Show("Nie można wyemitować faktury dla kontrahenta o id = " + knh_id.ToString() + " " + ex.Message);
}
ilosc_zrobionych++;
}
}

You are accessing a UI control from a background thread:
MTBDataZapisuDoFK.Text
That is not allowed.
Get this value before calling the method, store it in a variable and send the value as an argument to issueInvoices.

The problem is in getting the value of MTBDataZapisuDoFK.Text (which I assume to be a textbox). Getting or setting the text of a textbox means sending messages to its window. But you keep the UI-thread busy in the while loop and therefore it can not process any messages.
Put a call to Application.DoEvents() into the while loop to allow messages to be processed:
fpb.Show();
while (ilosc_zrobionych != liczbaKontrahentow)
{
Application.DoEvents();
fpb.PBStan.Value = (int)((100 * ilosc_zrobionych) / liczbaKontrahentow);
}
fpb.Close();
I assume that the only reason for calling the method asynchronously is to be able to update the UI during processing the WyemitujFakture-method. Using Application.DoEvents() you do not need asynchonous calls:
fpb = new FrmProgressBar("Please wait....");
fpb.Show();
Application.DoEvents();
WyemitujFakture(lista);
fpb.Close();
You should call Application.DoEvents() after you call fpb.Show() to allow the form to be displayed properly. Also you should instantiate the form in the method itself instead of the constructor, because you can not use the same instance again after calling fpb.Close() (it will be disposed).
Then you can update the progress bar in the WyemitujFakture-method:
private void WyemitujFakture(List<int> lista)
{
foreach (int knh_id in lista)
{
try
{
if (luk.Count > 0)
{
FakturySprzedazy fs = new FakturySprzedazy();
fs.FKS_AKCYZA = false;
fs.FKS_CZY_KLON = false;
fs.FKS_DATA_DOW_KS = Convert.ToDateTime(MTBDataZapisuDoFK.Text);
fs.FKS_DATA_FAKTURY = Convert.ToDateTime(MTBDataFaktury.Text);
fs.FKS_DATA_SPRZEDAZY = Convert.ToDateTime(MTBDataSprzedazy.Text);
liczbaWygenerowach++;
}
}
catch (Exception ex)
{
MessageBox.Show("Nie mozna wyemitowac faktury dla kontrahenta o id = " + knh_id.ToString() + " " + ex.Message);
}
ilosc_zrobionych++;
fpb.PBStan.Value = (int)((100 * ilosc_zrobionych) / liczbaKontrahentow);
Application.DoEvents();
}
}