I trying to write a server program with UI on c#.
the server is called from background worker->saparated thread. In the server' i have to update the UI about what cient connected on what prot, and also some other parameters.
I understand that i have to use the Invoke and i read about it, but somehow i can't implement it on my code. So here is my code, thanks ahead for any help:
enter code here
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Runtime.InteropServices;
using System.Net.Sockets;
using System.Threading;
using System.IO;
using System.Configuration;
using System.Collections;
namespace WindowsFormsApplication1
{
public partial class ServerAppMainDisplay : Form
{
public Int32 local_port = 40000;
public int StopOrSrart = 0;
public string localIP = "?";
public string myHostName = "?";
public string ServerIP = "Server IP: ";
public string DefaultPort = "Listening on default port: ";
public string MachineName = "Machine Name: ";
public static bool ThrdState = false;
public static bool TxtBoxVsblty = false;
public ServerAppMainDisplay()
{
InitializeComponent();
textBox2.Text = DefaultPort;
textBox1.Text = ServerIP;
textBox3.Text = MachineName;
textUpdate.ShowDialogs();
}
private void UpdateText(string text)
{
// Set the textbox text
textBox5.Text = text;
}
private void button1_Click(object sender, EventArgs e)
{
myHostName = Dns.GetHostName().ToString();
localIP = Dns.Resolve(myHostName).AddressList[0].ToString();
textBox1.Text = ServerIP + localIP;
textBox3.Text = MachineName + myHostName;
textBox2.Text = DefaultPort + local_port.ToString();
backgroundWorker1.RunWorkerAsync();
}
private void button2_Click(object sender, EventArgs e)
{
//Data Log txt
}
private void button3_Click(object sender, EventArgs e)
{
//Data Log Excel
}
private void button4_Click(object sender, EventArgs e)
{
DialogResult dialogResult = MessageBox.Show("Are you sure you want to stop server application?",
"Stop server application", MessageBoxButtons.YesNo);
if (dialogResult == DialogResult.Yes)
{
textBox2.Text = DefaultPort;
textBox1.Text = ServerIP;
textBox3.Text = MachineName;
myTCPServer.thread.Abort();
myTCPServer.listener.Stop();
myTCPServer.DefSoc.Dispose();
for (int i = 1; i < 10; i++)
{
if (myTCPServer.Connection[i].portFlag)
{
myTCPServer.Connection[i].slistener.Stop();
myTCPServer.Connection[i].socket.Dispose();
}
}
ThrdState = true;
TxtBoxVsblty = false;
}
if (dialogResult == DialogResult.No) return;
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
myTCPServer.myMain();
}
private void button5_Click(object sender, EventArgs e)
{
DialogResult dialogResult = MessageBox.Show("Are you sure you want to exit server window application?",
"Exit server window application", MessageBoxButtons.YesNo);
if (dialogResult == DialogResult.Yes)
{
backgroundWorker1.Dispose();
backgroundWorker1.CancelAsync();
myTCPServer.thread.DisableComObjectEagerCleanup();
myTCPServer.thread.Abort();
this.Close();
Application.Exit();
}
if (dialogResult == DialogResult.No) return;
}
}
public class myTCPServer
{
public static Socket DefSoc;
public static Thread thread = new Thread(new ThreadStart(Service));
public static TcpListener listener;
public struct Connection_s
{
public int port;
public bool portFlag;
public Socket socket;
public TcpListener slistener;
};
public static myTCPServer.Connection_s[] Connection = new myTCPServer.Connection_s[10];
public const int DefaultPort = 40000;
public static void myMain()
{
if (!WindowsFormsApplication1.ServerAppMainDisplay.ThrdState)
myTCPServer.thread.Start();
else
{
myTCPServer.thread = new Thread(new ThreadStart(Service));
myTCPServer.thread.Start();
}
}
public static void Service()
{
for (int i = 1; i < 10; i++)
{
Connection[i].portFlag = false;
Connection[i].port = DefaultPort + i;
}
myTCPServer.listener = new TcpListener(DefaultPort);
myTCPServer.DefSoc = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
while (true)
{
byte[] SndBfr;
string str;
myTCPServer.listener.Start();
if (myTCPServer.listener.Pending())
{
DefSoc = myTCPServer.listener.AcceptSocket();
for (int i = 1; i < 10; i++)
{
if (Connection[i].portFlag == false)
{
Thread.Sleep(10);
str = "<" + Connection[i].port as string;
SndBfr = System.Text.Encoding.UTF8.GetBytes(str);
DefSoc.Send(SndBfr);
Thread.Sleep(10);
Connection[i].slistener = new TcpListener(Connection[i].port);
Connection[i].slistener.Start();
Connection[i].socket = Connection[i].slistener.AcceptSocket();
Connection[i].portFlag = true;
yourTextBox.Invoke(new UpdateTextCallback(this.UpdateText),
new object[]{”Text generated on non-UI thread.”});
DefSoc.Disconnect(true);
DefSoc.Dispose();
myTCPServer.listener.Stop();
myTCPServer.listener = new TcpListener(DefaultPort);
myTCPServer.DefSoc = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
break;
}
}
}
Thread.Sleep(10);
for (int i = 1; i < 10; i++)
{
if (Connection[i].portFlag == true)
{
int SndRslt = 0;
str = DateTime.Now.ToString(#"MM\/dd\/yyyy h\:mm tt");
try
{
SndRslt = Connection[i].socket.Send(System.Text.Encoding.UTF8.GetBytes("+" + str));
}
catch (SocketException) { }
if (SndRslt <= 0)
{
try
{
Connection[i].portFlag = false;
Connection[i].socket.Disconnect(true);
Connection[i].slistener.Stop();
}
catch (SocketException) { }
}
}
}
}
}
}
}
Change your UpdateText(string text) to this:
private void UpdateText(string text)
{
if(textBox5.InvokeRequired)
{
Action a = () => UpdateText(text);
Invoke(a);
}
else
textBox5.Text = text;
}
This will invoke the textbox if required.
Invoke From MSDN
The Invoke method searches up the control's parent chain until it
finds a control or form that has a window handle if the current
control's underlying window handle does not exist yet. If no
appropriate handle can be found, the Invoke method will throw an
exception. Exceptions that are raised during the call will be
propagated back to the caller.
You should go for "MethodInvoker" for cross-thread [Moreover, to ensure the "Method" executes on GUI thread]
Maybe this could help:
MethodInvoker method = delegate{
yourTextBox.Text = "the text you need";
};
if (InvokeRequired) // You may skip this
BeginInvoke(method);
Invoke a delegate to the function that updates the UI and use InvokeRequired in the function to check if the delegate needs to be called.
Example:
Imports System.Management
Private watcher As New ManagementEventWatcher
//delegate to udater UI function
Delegate Sub SetItemCallback(ByVal item As ListViewItem)
Private item1 As ListViewItem
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim query As New WqlEventQuery("Win32_ProcessStartTrace")
watcher.Query = query
AddHandler watcher.EventArrived, AddressOf EventWorker
watcher.Start()
End Sub
'This method start when event arrived. It's invoked from another thead. (not UI thread)
Public Sub EventWorker(ByVal sender As Object, ByVal e As System.Management.EventArrivedEventArgs)
Try
Dim mbo As ManagementBaseObject = e.NewEvent
For Each p As PropertyData In mbo.Properties
item1 = New ListViewItem(p.Name)
If p.Value IsNot Nothing Then : item1.SubItems.Add(p.Value.ToString)
Else : item1.SubItems.Add(String.Empty)
End If
'updates de UI
Me.SetItem(item1)
Next
Catch ex As Exception
Console.WriteLine(ex.Message)
End Try
End Sub
'If InvokeRequired (no UI thread) create the delegate and invoke it else update the UI
Private Sub SetItem(ByVal itm As ListViewItem)
If Me.ListView1.InvokeRequired Then
Dim d As New SetItemCallback(AddressOf SetItem)
Me.Invoke(d, New Object() {itm})
Else
ListView1.Items.Add(itm)
End If
End Sub
Private Sub Form1_FormClosed(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
watcher.Stop()
End Sub
Related
I have a made a small tool which gets file size and name of the URL but it takes time (approx 4 seconds) when I run the code and enter a file URL it takes time for the user it will look like it is not working.
I want to show a progress bar until the data is received so that user may not think that the application is not working.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Multi_Tool
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button2_Click(object sender, EventArgs e)
{
{
if (textBox1.Text == "")
{
MessageBox.Show("You have not typed the URL", "URL Error",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
else
{
string URL = textBox1.Text;
string filetype = URL.Substring(URL.LastIndexOf(".") + 1,
(URL.Length - URL.LastIndexOf(".") - 1));
FileType.Text = filetype.ToUpper();
string filename = URL.Substring(URL.LastIndexOf("/") + 1,
(URL.Length - URL.LastIndexOf("/") - 1));
namelabel.Text = filename;
System.Net.WebRequest req = System.Net.HttpWebRequest.Create(textBox1.Text);
req.Method = "HEAD";
System.Net.WebResponse resp = req.GetResponse();
long ContentLength = 0;
long result;
if (long.TryParse(resp.Headers.Get("Content-Length"), out ContentLength))
{
string File_Size;
if (ContentLength >= 1073741824)
{
result = ContentLength / 1073741824;
kbmbgb.Text = "GB";
}
else if (ContentLength >= 1048576)
{
result = ContentLength / 1048576;
kbmbgb.Text = "MB";
}
else
{
result = ContentLength / 1024;
kbmbgb.Text = "KB";
}
File_Size = result.ToString("0.00");
sizevaluelabel.Text = File_Size;
}
}
}
}
private void button1_Click(object sender, EventArgs e)
{
textBox1.Clear();
}
}
}
You can use a background worker to move your downloading to another thread and showing a progress bar until the data is received.
ProgressForm is a form which contains progress bar which you can show until data is downloaded
this.progressBar1 = new System.Windows.Forms.ProgressBar();
//
// progressBar1
//
this.progressBar1.Location = new System.Drawing.Point(12, 30);
this.progressBar1.MarqueeAnimationSpeed = 1;
this.progressBar1.Maximum = 2500;
this.progressBar1.Name = "progressBar1";
this.progressBar1.Size = new System.Drawing.Size(522, 23);
this.progressBar1.Style = System.Windows.Forms.ProgressBarStyle.Marquee;
this.progressBar1.TabIndex = 1;
//constructor
public frmProgress(string text)
{
this.Text = text;
InitializeComponent();
}
If you want to show value in your progress bar make sure to change the properties back to normal(which are set as marquee in answer as of now).But as you said it is going to take just 4 secs it would be good to use marquee
//Method to increment value of progress bar
public void PrgBarInc()
{
if (this.IsHandleCreated)
{
if (this.InvokeRequired)
{
this.Invoke(new MethodInvoker(PrgBarInc));
}
else
{
prgBar.Increment("your val");
}
}
==============================Main UI class==============================
BackgroundWorker backgroundWorker1 = new System.ComponentModel.BackgroundWorker();
this.backgroundWorker1.DoWork += new System.ComponentModel.DoWorkEventHandler(this.backgroundWorker1_DoWork);
this.backgroundWorker1.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(this.backgroundWorker1_RunWorkerCompleted);
//Add In your method which initiates download
public void PerformDownload()
{
ProgressForm = new frmProgress("your text");
ProgressForm.ShowInTaskbar = false;
backgroundWorker1.RunWorkerAsync();
ProgressForm.ShowDialog();
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
//perform service request
//if any of your task gets compeleted just call
//ProgressForm.PrgBarInc()
}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
ProgressForm.Close();
ProgressForm.Dispose();
}
Normally, you update the progress bar like this:
progressBar1.Value = N;
Wrapping it within BeginInvoke() makes the UI responsive:
Dispatcher.BeginInvoke(DispatcherPriority.Normal,
new DispatcherOperationCallback(delegate
{
progressBar1.Value = progressBar1.Value + 1;
//update in UI Thread
return null;
}), null);
I've got a weird issue here. I'll start by explaining my program:
I have a C# application. The main goal of the program is to get information about a book based on its ISBN. The ISBN is passed to the program via a TCP/IP scanner on an Android device. The ISBN is then put into a valid URL which is used to grab the XML data from ISBNDB.com.
The issue that I am having is this:
When I query an ISBN typed into a TextBox, the program works fine. When I query an ISBN scanned from the reader, it returns 'No Results'
I have implemented various ways to try and get to the bottom of this case. Right before the XML is read, I have a message box show me the XML that it received:
As you can see, it shows no results. However, when I visit the URL (Also gotten from within the program):
I get this in Microsoft Edge:
Which, is exactly what I would think the application would get as well.
Does anyone know what is going on? If so, what can I do to fix it and how can my code be improved to eliminate this error?
For those interested, here is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Xml;
using System.Threading;
using System.Diagnostics;
namespace LibraryBookLister
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
string XML = "";
private void btnQuery_Click(object sender, EventArgs e)
{
GetXMLBarcodeData();
}
private void GetXMLBarcodeData()
{
string Barcode4 = textBarcode.Text;
MessageBox.Show(Barcode4);
string barcode = Barcode4;
StringBuilder output = new StringBuilder();
XmlUrlResolver resolver = new XmlUrlResolver();
resolver.Credentials = System.Net.CredentialCache.DefaultCredentials;
// Set the reader settings object to use the resolver.
if(barcode.Length > 13)
{
barcode = barcode.Remove(14);
MessageBox.Show(barcode);
}
string xmlString = #"?access_key=IDC057UX&results=details&index1=isbn&value1=" + barcode;
MessageBox.Show("GEttting book info for : " + barcode);
Uri baseUri = new Uri("https://isbndb.com/api/books.xml");
Uri fulluri = resolver.ResolveUri(baseUri, xmlString);
MessageBox.Show("Now Getting The URL: " + fulluri.ToString());
Process.Start(fulluri.ToString());
StringBuilder sb = new StringBuilder();
XmlReader readesr = XmlReader.Create(fulluri.ToString());
MessageBox.Show("REading data from " + fulluri.ToString());
while (readesr.Read())
{
sb.AppendLine(readesr.ReadOuterXml());
}
string XMLs = sb.ToString();
XML = XMLs;
MessageBox.Show("XML : " + XML);
GetXMLStuff();
}
public void GetXMLStuff()
{
tcplistener.Stop();
XmlDocument doc = new XmlDocument();
doc.LoadXml(XML);
XmlNodeList nodes = doc.DocumentElement.SelectNodes("/ISBNdb/BookList");
List<Book> books = new List<Book>();
foreach (XmlNode node in nodes)
{
Book book = new Book();
try
{
if (node.SelectSingleNode("BookData/AuthorsText").InnerText == null)
{
MessageBox.Show("Could not find this book. Please enter data by hand.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
textBarcode.Clear();
return;
}
}
catch
{
MessageBox.Show("Could not find this book. Please enter data by hand.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
// textBarcode.Clear();
return;
}
book.author = node.SelectSingleNode("BookData/AuthorsText").InnerText;
book.title = node.SelectSingleNode("BookData/Title").InnerText;
book.ISBN = node.SelectSingleNode("BookData").Attributes["isbn"].Value;
books.Add(book);
MessageBox.Show(book.author);
addInfo(book.author, book.title, book.ISBN);
textBarcode.Clear();
}
// MessageBox.Show("Total books: " + books.Count);
}
private void addInfo(string Author, string Title, string ISBN)
{
textAuthor.Text = Author;
textTitle.Text = Title;
textISBN.Text = ISBN;
}
class Book
{
public string ISBN;
public string title;
public string author;
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void groupBox1_Enter(object sender, EventArgs e)
{
}
int time = 10;
bool cancel = false;
private void timer1_Tick(object sender, EventArgs e)
{
if(time > 0)
{
labelTime.Text = time.ToString();
button1.Text = "Change Data";
cancel = true;
labelTime.Visible = true;
time--;
// MessageBox.Show(time.ToString());
}
if(time <= 0)
{
cancel = false;
button1.Text = "Add to List";
timer1.Stop();
time = 10;
labelTime.Visible = false;
MessageBox.Show("Submitting");
}
}
private void button1_Click(object sender, EventArgs e)
{
if(cancel)
{
timer1.Stop();
labelTime.Visible = false;
time = 10;
cancel = false;
button1.Text = "Add to List";
}
else
{
timer1.Start();
}
}
private void button2_Click(object sender, EventArgs e)
{
Thread tcpServer = new Thread(new ParameterizedThreadStart(TCPServerRun));
//TCPServerRun();
tcpServer.Start();
}
bool on = true;
TcpListener tcplistener = new TcpListener(IPAddress.Any, 5004);
private void TCPServerRun(object test)
{
try
{
MessageBox.Show("Starting Listener");
tcplistener.Start();
}
catch { MessageBox.Show("COULDNT START TPCSERVER"); return; }
while (on == true)
{
try
{
TcpClient client = tcplistener.AcceptTcpClient();
Thread tcpHandlerThread = new Thread(new ParameterizedThreadStart(tcpHandler));
// tcpHandlerThread.Start(client);
tcpHandler(client);
}
catch
{
tcplistener.Stop();
// MessageBox.Show("Stopping Listener");
}
}
}
string bCode = "";
private void tcpHandler(object client)
{
TcpClient mClient = (TcpClient)client;
NetworkStream stream = mClient.GetStream();
byte[] message = new byte[1024];
stream.Read(message, 0, message.Length);
bCode = Encoding.ASCII.GetString(message);
stream.Close();
mClient.Close();
MessageBox.Show(bCode);
this.textBarcode.Text = bCode;
GetXMLBarcodeData();
}
}
}
Possible Hint: Could it have something to do with how I have threads working?
*Edit: * **I have updated the code to have the barcode be put in a textBox and then used to fetch the data. This does not seem to work either because it 'Cannot access the control on a thread other than on which it was created'
If manual user input succeed while automated input fail, the simplest hack is just replacing the automated input to a call to manual control BeginInvoke. For your code this would be :
textBarcode.BeginInvoke(new Action(() => {
textBarcode.Text = bCode;
GetXMLBarcodeData();
}));
I have an application that scans the local network for connected PC's.
I want to get the client information (IP address, MAC address, Host name...) and the connection state (download rate, upload rate), and put them in the ListView, but the problem is that this information is not constant!
How could I get this information in real time? The info in the ListView changes every time the info of the client changes?
My current code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Collections;
using System.Text;
using System.Windows.Forms;
using NetUtils;
using System.Net;
namespace WindowsFormsApplication5
{
public partial class Form1 : Form
{
private IPScanner _scanner;
private class HostSorterByIP : IComparer
{
public int Compare(object x, object y)
{
byte[] bytes1 = ((IPScanHostState)((ListViewItem)x).Tag).Address.GetAddressBytes();
byte[] bytes2 = ((IPScanHostState)((ListViewItem)y).Tag).Address.GetAddressBytes();
int i = bytes1.Length - 1;
for (; i > 0 && bytes1[i] == bytes2[i]; i--)
;
return bytes1[i] - bytes2[i];
}
}
public Form1()
{
InitializeComponent();
_scanner = new IPScanner((int)_spnConcurrentPings.Value, (int)_spnPingsPerScan.Value, _cbContinuousScan.Checked,
(int)_spnTimeout.Value, (int)_spnTTL.Value, _cbDontFragment.Checked, (int)_spnBufferSize.Value);
_scanner.OnAliveHostFound += new IPScanner.AliveHostFoundDelegate(_scanner_OnAliveHostFound);
_scanner.OnStartScan += new IPScanner.ScanStateChangeDelegate(_scanner_OnStartScan);
_scanner.OnStopScan += new IPScanner.ScanStateChangeDelegate(_scanner_OnStopScan);
_scanner.OnRestartScan +=new IPScanner.ScanStateChangeDelegate(_scanner_OnRestartScan);
_scanner.OnScanProgressUpdate +=new IPScanner.ScanProgressUpdateDelegate(_scanner_OnScanProgressUpdate);
_lvAliveHosts.ListViewItemSorter = new HostSorterByIP();
_cmbRangeType.SelectedIndex = 0;
}
private void _scanner_OnAliveHostFound(IPScanner scanner, IPScanHostState host)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanner.AliveHostFoundDelegate(_scanner_OnAliveHostFound), scanner, host);
return;
}
ListViewItem item = new ListViewItem();
item.Tag = host;
item.BackColor = Color.GreenYellow;
item.SubItems.Add(host.Address.ToString());
item.SubItems.Add("");
item.SubItems.Add("");
item.SubItems.Add("");
_lvAliveHosts.Items.Add(item);
_lvAliveHosts.Sort();
host.OnHostNameAvailable += new IPScanHostState.HostNameAvailableDelegate(host_OnHostNameAvailable);
host.OnStateChange += new IPScanHostState.StateChangeDelegate(host_OnStateChange);
if (!host.IsTesting())
{
item.ImageIndex = (int)host.QualityCategory;
item.SubItems[2].Text = host.AvgResponseTime.ToString("F02") + " ms";
item.SubItems[3].Text = ((float)(host.LossCount) / host.PingsCount).ToString("P");
item.SubItems[4].Text = host.HostName;
}
//AddLogEntry("Host [" + host.Address.ToString() + "] is alive.");
Timer newTimer = new Timer();
newTimer.Tag = item;
newTimer.Interval = 2000;
newTimer.Tick += new EventHandler(newTimer_Tick);
newTimer.Enabled = true;
}
void host_OnHostNameAvailable(IPScanHostState host)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanHostState.HostNameAvailableDelegate(host_OnHostNameAvailable), host);
return;
}
ListViewItem item = FindListViewItem(host);
if (item != null)
item.SubItems[4].Text = host.HostName;
}
private ListViewItem FindListViewItem(IPScanHostState host)
{
foreach (ListViewItem item in _lvAliveHosts.Items)
{
if (item.Tag == host)
return item;
}
return null;
}
private void host_OnStateChange(IPScanHostState host, IPScanHostState.State oldState)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanHostState.StateChangeDelegate(host_OnStateChange), host, oldState);
return;
}
if (!host.IsTesting())
{
ListViewItem item = FindListViewItem(host);
if (item != null)
{
if (host.IsAlive())
{
item.ImageIndex = (int)host.QualityCategory;
item.SubItems[2].Text = host.AvgResponseTime.ToString("F02") + " ms";
item.SubItems[3].Text = ((float)(host.LossCount) / host.PingsCount).ToString("P");
}
else
{
//AddLogEntry("Host [" + host.Address.ToString() + "] died.");
host.OnStateChange -= host_OnStateChange;
host.OnHostNameAvailable -= host_OnHostNameAvailable;
item.BackColor = Color.IndianRed;
Timer removeTimer = new Timer();
removeTimer.Tag = item;
removeTimer.Interval = 2000;
removeTimer.Tick += new EventHandler(removeTimer_Tick);
removeTimer.Enabled = true;
}
}
}
}
void newTimer_Tick(object sender, EventArgs e)
{
Timer timer = (Timer)sender;
timer.Stop();
timer.Tick -= newTimer_Tick;
ListViewItem item = (ListViewItem)timer.Tag;
item.BackColor = Color.White;
}
void removeTimer_Tick(object sender, EventArgs e)
{
Timer timer = (Timer)sender;
timer.Stop();
timer.Tick -= newTimer_Tick;
ListViewItem item = (ListViewItem)timer.Tag;
_lvAliveHosts.Items.Remove(item);
}
private void _scanner_OnStartScan(IPScanner scanner)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanner.ScanStateChangeDelegate(_scanner_OnStartScan), scanner);
return;
}
foreach (ListViewItem item in _lvAliveHosts.Items)
{
((IPScanHostState)item.Tag).OnStateChange -= host_OnStateChange;
((IPScanHostState)item.Tag).OnHostNameAvailable -= host_OnHostNameAvailable;
}
_lvAliveHosts.Items.Clear();
_prgScanProgress.Value = 0;
EnableSettings(false);
}
private void EnableSettings(bool enable)
{
_cmbRangeType.Enabled = _tbRangeStart.Enabled = _tbRangeEnd.Enabled = _spnTimeout.Enabled = _spnTTL.Enabled = _spnBufferSize.Enabled = _cbDontFragment.Enabled =
_spnConcurrentPings.Enabled = _spnPingsPerScan.Enabled = _cbContinuousScan.Enabled = enable;
_btnStartStop.Text = enable ? "&Start" : "&Stop";
if (enable)
_prgScanProgress.Text = "Scanner is not running!";
}
private void _btnStartStop_Click(object sender, EventArgs e)
{
if (!_scanner.Active)
{
try
{
_scanner.Start(_cmbRangeType.SelectedIndex == 0
? new IPScanRange(IPAddress.Parse(_tbRangeStart.Text), IPAddress.Parse(_tbRangeEnd.Text))
: new IPScanRange(IPAddress.Parse(_tbRangeStart.Text), int.Parse(_tbRangeEnd.Text)));
}
catch (FormatException)
{
MessageBox.Show(this, "Cannot parse IP range or subnetmask!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
else
_scanner.Stop(false);
}
private void _scanner_OnStopScan(IPScanner scanner)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanner.ScanStateChangeDelegate(_scanner_OnStopScan), scanner);
return;
}
EnableSettings(true);
_prgScanProgress.Value = 0;
}
void _scanner_OnRestartScan(IPScanner scanner)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanner.ScanStateChangeDelegate(_scanner_OnRestartScan), scanner);
return;
}
_prgScanProgress.Value = 0;
}
void _scanner_OnScanProgressUpdate(IPScanner scanner, IPAddress currentAddress, ulong progress, ulong total)
{
if (InvokeRequired)
{
BeginInvoke(new IPScanner.ScanProgressUpdateDelegate(_scanner_OnScanProgressUpdate), scanner, currentAddress, progress, total);
return;
}
int prog = (int)((100 * progress) / total);
_prgScanProgress.Value = prog;
_prgScanProgress.Text = prog.ToString() + "%" + " [" + currentAddress.ToString() + "]";
}
private void _cmbRangeType_SelectedIndexChanged(object sender, EventArgs e)
{
if (_cmbRangeType.SelectedIndex == 0)
{
_lRangeSep.Text = "-";
_lRangeEnd.Text = "Range &End:";
_tbRangeEnd.Size = new Size(130, _tbRangeEnd.Size.Height);
}
else
{
_lRangeSep.Text = "/";
_lRangeEnd.Text = "Subnet &Mask:";
_tbRangeEnd.Size = new Size(32, _tbRangeEnd.Size.Height);
}
}
//private void _lvAliveHosts_DoubleClick(object sender, EventArgs e) { _btnAddHost_Click(sender, e); }
private void IPScanForm_FormClosing(object sender, FormClosingEventArgs e) { _scanner.Stop(true); }
private ListViewItem.ListViewSubItem _activeTooltipSubitem = null;
private static string[] QualityCategoryNames = { "Very Poor", "Poor", "Fair", "Good", "Very Good", "Excellent", "Perfect" };
private void _lvAliveHosts_MouseMove(object sender, MouseEventArgs e)
{
ListViewItem item = _lvAliveHosts.HitTest(e.Location).Item;
if (item != null)
{
ListViewItem.ListViewSubItem subitem = _lvAliveHosts.HitTest(e.Location).SubItem;
if (subitem != null && item.SubItems.IndexOf(subitem) == 0)
{
if (_activeTooltipSubitem != subitem)
{
_ttQuality.Show("Quality: " + QualityCategoryNames[item.ImageIndex], _lvAliveHosts, item.SubItems[1].Bounds.X, subitem.Bounds.Y);
_activeTooltipSubitem = subitem;
}
return;
}
}
_activeTooltipSubitem = null;
_ttQuality.Hide(_lvAliveHosts);
}
}
}
I would create the list of clients and show them in the listview.
Than, in a background thread, every X seconds, poll all of the current clients.
Next , compare the list of updated clients to a list of clients from last update.
What remain to do is to add any new client to the list, and remove any client which no longer exists.
Pay attention to the context, use InvokeRequired() to get access to the UI control from the background thread.
EDIT:
here is how to run a background thread:
static void Main(string[] args)
{
Thread worker = new Thread(DoBackgroundWork);
}
public static void DoBackgroundWork()
{
while (true)
{
//Sleep 10 seconds
Thread.Sleep(10000);
//Do some work and than post to the control using Invoke()
}
}
I am trying to build a chat, basically i used the invoke function what a thread.
I am able to read what the server sends me, but i am able to write only once. i am trying to finish this but not sure how to write to server each time the server:
(take into account that i wrote this before in console application form and the server works fine... i.e. the problem isnt with the server).
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
Button btn1 = new Button();
btn1.Click += button1_Click;
}
StreamReader sr;
StreamWriter sw;
TcpClient connection;
private void Form1_Load(object sender, EventArgs e)
{
connection = new TcpClient("127.0.0.1", 5000);
sr = new StreamReader(connection.GetStream());
sw = new StreamWriter(connection.GetStream());
}
private void button2_Click(object sender, EventArgs e)
{
Thread t2 = new Thread(Reader);
t2.Start(connection);
}
string msg;
public void Reader(object o)
{
TcpClient con = o as TcpClient;
if (con == null)
return;
while (true)
{
msg = sr.ReadLine();
Invoke(new Action(Output));
}
}
public void Output()
{
ChatScreen.Text = msg;//set the message on the screen
}
string textinput;
private void button1_Click(object sender, EventArgs e)
{
textinput = InputLine.Text;
sw.WriteLine(textinput);// this thing, writes once, multiple clicks wont send a new line to the server :(..the problem is in this button
sw.Flush();
}
}
what I thought to do is to connect the button so it will be able to do multiple clicks ..e.g btn.Click()..or run a thread with invoke on the WriteLine (but my intuition says that making the button click several times would make the program work
You need to stop the thread process when you close the form, if not when you try to do the invoke, it will fail because the form is disposed and it can't be used to do an invoke. You can override the dispose method to stop the reader thread or you can do it on the onclose method. Or you can check on the reader process if the control it's available (it is not disposed) and if it's not available finish the read process.
You should prevent that the reader process will be launch multiple times too, to prevent errors, so you need to disable the button when the thread is run.
Edited:
You can use something like the following code to read multiple lines and to stop the thread when you close the form.
private bool mbIsRunning = true;
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
lock (this)
{
mbIsRunning= false;
}
}
private bool IsRunning
{
get
{
lock(this)
{
return mbIsRunning;
}
}
}
string msg;
public void Reader(object o)
{
TcpClient con = o as TcpClient;
if (con == null)
return;
while (IsRunning)
{
msg = reader.ReadLine();
string line;
while( (line = reader.ReadLine()) != null )
{
msg = msg + Enviroment.NewLine + line;
}
Invoke(new Action(Output));
}
}
Running up your code, I get a bunch of errors - from the TcpClient throwing an exception and so on.
However, assuming that you haven't posted all of your code, I would recommend putting a try...catch around all of your functions, and then breakpoints in the catch to see what the problem is. Examine the exceptions - exceptions should only be thrown in exceptional circumstances - so your code should really work without doing that.
I do concat on my server code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Threading;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
TcpListener server = new TcpListener(IPAddress.Any, 5000);
server.Start();
Console.WriteLine("Server started");
string word = "";
savedObject saved = new savedObject();
while (true)
{
TcpClient connection = server.AcceptTcpClient();
Console.WriteLine("connection accepted");
ThreadPool.QueueUserWorkItem(saved.ProssecClient, connection);
}
}
}
}
class savedObject
{
Dictionary<string, StreamWriter> dic = new Dictionary<string, StreamWriter>();
StreamReader[] sr1 = new StreamReader[100];
StreamWriter[] sw1 = new StreamWriter[100];
string[] name = new string[100];
int m;
int a;
int g;
string word;
public string AllWords(string sit)
{
word += sit + " ";// here i concat them
return word;
}
public string word2()
{
return word;
}
public void ProssecClient(object o)
{
TcpClient connection = o as TcpClient;
if (connection == null)
{
return;
}
StreamReader sr = new StreamReader(connection.GetStream());
StreamWriter sw = new StreamWriter(connection.GetStream());
sr1[a++] = new StreamReader(connection.GetStream());
sw1[m++] = new StreamWriter(connection.GetStream());
string word2 = "";
sw.WriteLine("Please, fill your name: ");
name[g++] = sr.ReadLine();
if (name[g] != null && sw1[m] != null)
{
dic.Add(name[g], sw1[m]);
}
try
{
while (true)
{
int i = 0;
word2 = AllWords(sr.ReadLine());
for (i = 0; i < 3; i++)
{
if (sw1[i] != null)
{
sw1[i].WriteLine( name[i] + ": " + word2);// here is the words that are sent..
sw1[i].Flush();
}
}
}
}
catch { Console.WriteLine("client left"); }
}
}
This is one of my first issues. Whenever I exit out the program, tcpClient.Connect() takes forever to close. I've tried a ton of things, and none of them seem to work.
Take a look at the CreateConnection() thread, if the client isn't connected yet... and I close the program, it takes forever to close. If it IS connected, it closes immediately. I know this can be done with some kind of timeout trick, but i've tried a few and none of them worked.
Please provide a code example if you can.
Also, is there any good tutorial out there for C# on reading/writing the actual bytes with a buffer instead of this version that just does masterServer.writeLine() and masterServer.readline() or are they both just as efficient?
If you see anything else to help me improve this... by all means, go ahead. I'm trying to teach myself how to do this and I have no help, so don't let me go on doing something wrong if you see it!!! Thanks guys!
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.IO;
namespace RemoteClient
{
public partial class Form1 : Form
{
private int MyPort = 56789;
private IPAddress myIp = IPAddress.Parse("210.232.115.79");
private IPAddress serverIp = IPAddress.Parse("72.216.18.77"); // Master Server's IP Address
public static TcpClient masterServer = new TcpClient();
private StreamWriter responseWriter;
private StreamReader commandReader;
private Thread connectionThread;
private Thread commandsThread;
private bool RequestExitConnectionThread { get; set; }
private delegate void AddMessageDelegate(string message, int category);
private delegate void ConnectedDelegate();
private bool isConnected { get; set; }
public Form1()
{
InitializeComponent();
isConnected = false;
}
private void LogMessage(string message, int category)
{
if (category == 1)
{
ListViewItem item = new ListViewItem(message);
item.BackColor = Color.LightGreen;
item.UseItemStyleForSubItems = true;
Log.Items.Add(item).SubItems.Add(DateTime.Now.ToString());
}
if (category == 2)
{
ListViewItem item = new ListViewItem(message);
item.BackColor = Color.Orange;
item.UseItemStyleForSubItems = true;
Log.Items.Add(item).SubItems.Add(DateTime.Now.ToString());
}
if (category == 3)
{
ListViewItem item = new ListViewItem(message);
item.BackColor = Color.Yellow;
item.UseItemStyleForSubItems = true;
Log.Items.Add(item).SubItems.Add(DateTime.Now.ToString());
}
if (category == 0)
{
Log.Items.Add(message).SubItems.Add(DateTime.Now.ToString());
}
}
private void Connected()
{
LogMessage("Found and Accepted Master Server's connection. Waiting for reply...",1);
Status.Text = "Connected!";
Status.ForeColor = Color.Green;
commandsThread = new Thread(new ThreadStart(RecieveCommands));
sendClientInfo();
}
private void exitButton_Click(object sender, EventArgs e)
{
Disconnect();
exitButton.Enabled = false;
exitButton.Text = "Closing...";
if (connectionThread != null)
{
while (connectionThread.IsAlive)
{
Application.DoEvents();
}
}
this.Close();
}
private void Form1_Load(object sender, EventArgs e)
{
Connect();
}
private void Disconnect()
{
RequestExitConnectionThread = true;
if (masterServer != null)
masterServer.Close();
if (connectionThread != null)
connectionThread.Abort();
LogMessage("Closing Client. Please wait while Program threads end.", 2);
}
private void Disconnected()
{
Status.Text = "Disconnected";
Status.ForeColor = Color.Red;
Connect();
}
private void Connect()
{
LogMessage("Attempting to connect to Master Server...", 1);
connectionThread = new Thread(new ThreadStart(CreateConnection));
connectionThread.Start();
}
private void CreateConnection()
{
int i = 1;
bool success = false;
while (!success)
{
try
{
using (masterServer = new TcpClient())
{
IAsyncResult result = masterServer.BeginConnect(serverIp, MyPort, null, null);
success = result.AsyncWaitHandle.WaitOne(1000, false);
}
if (success)
{
BeginInvoke(new ConnectedDelegate(this.Connected), new object[] {});
break;
}
else
{
Thread.Sleep(2000);
BeginInvoke(new AddMessageDelegate(LogMessage), new object[] { "Connection Retry # " + i.ToString() + ". Master Server hasn't been started yet.", 3 });
}
}
catch
{
MessageBox.Show("Error!");
}
i++;
}
}
private void RecieveCommands()
{
MessageBox.Show("Hello!");
commandReader = new StreamReader(masterServer.GetStream());
string CommandResponse = commandReader.ReadLine();
string Command = null;
if (CommandResponse != null)
MessageBox.Show("Recieved Command that was NOT null!");
if (CommandResponse != null)
{
MessageBox.Show("Recieved null response!");
BeginInvoke(new AddMessageDelegate(LogMessage), new object[] { "Disconnected From Master Server. Reason: Recieved Null response.", 1 });
Disconnected();
}
else if (CommandResponse.StartsWith("0"))
{
MessageBox.Show("Recieved 0 as a response!");
Command = CommandResponse.Substring(2).Trim();
isConnected = false;
BeginInvoke(new AddMessageDelegate(LogMessage), new object[] { "Disconnected From Master Server. Reason: " + Command, 1 });
}
else if (CommandResponse.StartsWith("1"))
{
MessageBox.Show("Recieved 1 as a response!");
isConnected = true;
BeginInvoke(new AddMessageDelegate(LogMessage), new object[] { "Connected to Master Server Successfully.", 1 });
}
}
//************************** RESPONSE'S BELOW HERE ************************* \\
private void sendClientInfo()
{
responseWriter = new StreamWriter(masterServer.GetStream());
responseWriter.WriteLine(myIp.ToString());
responseWriter.Flush();
}
}
}
Sorry, after testing it: NO, it does not use an async waithandle, it blocks the process :(
I prefer this solution, which also blocks the process but only by the period you specify, in this case 5 seconds:
using (TcpClient tcp = new TcpClient())
{
IAsyncResult ar = tcp.BeginConnect("127.0.0.1", 80, null, null);
System.Threading.WaitHandle wh = ar.AsyncWaitHandle;
try
{
if (!ar.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(5), false))
{
tcp.Close();
throw new TimeoutException();
}
tcp.EndConnect(ar);
}
finally
{
wh.Close();
}
}
From: http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/2281199d-cd28-4b5c-95dc-5a888a6da30d
The following example uses both async connection and async timeout control:
var tcp = new TcpClient();
var ar = tcp.BeginConnect(Ip, Port, null, null);
Task.Factory.StartNew(() =>
{
var wh = ar.AsyncWaitHandle;
try
{
if (!ar.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(5), false))
{
// The logic to control when the connection timed out
tcp.Close();
throw new TimeoutException();
}
else
{
// The logic to control when the connection succeed.
tcp.EndConnect(ar);
}
}
finally
{
wh.Close();
}
});
connect with timeout of 2000 ms:
AutoResetEvent connectDone = new AutoResetEvent( false );
TcpClient client = new TcpClient();
client.BeginConnect(
"127.0.0.1", 80,
new AsyncCallback(
delegate( IAsyncResult ar ) {
client.EndConnect( ar );
connectDone.Set();
}
), client
);
if( !connectDone.WaitOne( 2000 ) ) {
Console.WriteLine( "network connection failed!" );
Environment.Exit( 0 );
}
Stream stream = client.GetStream();
Adding a check within your connection process to cancel it if the program is exiting should help.
Try adding this in CreateConnection() inside your while(!success) loop but before your try block:
if(RequestExitConnectionThread)
{
break;
}
Here's an example of an asynchronous BeginConnect() call:
myTcpClient.BeginConnect("localhost", 80, OnConnect, null);
OnConnect function:
public static void OnConnect(IAsyncResult ar)
{
// do your work
}