c# listbox not working
I am attempting to add a username to a listbox at runtime as they connect to my server app. The listbox is updated when i check it in the code, i.e. when i debug the code, all the entrys are displayed, however, the actual listbox on the display is never updated, if i put the command in the form load the item is added.
I have tryed a this.refresh, lstItems.Update(), lstItems.Refresh() all dont work
Thanks
Tom
I have tryed a this.refresh, lstItems.Update(), lstItems.Refresh() all dont work
Thanks
Tom
lstItems.Item.Add(Username);
ASKER
I tried all 3 after the update of the list box and yes, i was typing the code, the actual code is below.
public void AddUser(string Name)
{
//Add the user onto the
lstUsers.Items.Add(Name);
lstUsers.Refresh();
}
have you tried refreshing the form itself?
ASKER
yes, i have used this.refresh();
are you shure that you are filling correct listbox?
look on items list in debug mode (breakepoint)
check name of the control
make sample test application
look on items list in debug mode (breakepoint)
check name of the control
make sample test application
ASKER
I am filling the correct list box, i only have one list box on my form at the moment.
the code is above
when i debug the code the count has gone up and if show the last entry in the list box in a message box, i.e. MessageBox.Show (lstUser.Items[lstUsers.It
the code is above
when i debug the code the count has gone up and if show the last entry in the list box in a message box, i.e. MessageBox.Show (lstUser.Items[lstUsers.It
put whole your application..
i made simple application and i haven't any problem..
everythinks works good even without refresh
i made simple application and i haven't any problem..
everythinks works good even without refresh
private void button1_Click(object sender, EventArgs e)
{
listBox1.Items.Add("xxxx");
}
ASKER
This is the main form
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.Net;
using System.Net.Sockets;
using System.IO;
namespace STD_Server
{
public partial class frmMain : Form
{
#region//Varaibles\\
public bool bolOnline = false,
bolRaw = true;
#endregion
#region//Constants\\
public const string _strOfflineLabel = "The server is offline",
_strOnlineLabel = "The server is online and accepting connections to ",
_strOfflineButton = "Put Server Online",
_strProgramName = "Server Transmitted Data",
_strProgramAbbrivation = "STD";
public const int _intMaxUsers = 30;
#endregion
private delegate void UpdateStatusCallback(string strMessage);
public frmMain()
{
InitializeComponent();
}
/// <summary>
/// Sets up the initial variables for the server
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
/// <AuthorName>TT</AuthorName>
/// <DateWritten>08/04/2009</DateWritten>
private void frmMain_Load(object sender, EventArgs e)
{
//Stats Variables TT\\
bolOnline = false;
chkRaw.Checked = true;
bolRaw = true;
}
#region//Server Status\\
/// <summary>
/// Switch the server state
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void cmdStatus_Click(object sender, EventArgs e)
{
//Check which state the server is in TT\\
if (!bolOnline)
{
//The server is offline, run the put online script TT\\
PutServerOnline();
}
}
/// <summary>
/// Puts the server into the online state
/// </summary>
/// <returns name="Success"></returns>
/// <AuthorName>TT</AuthorName>
/// <DateWritten>08/04/2009</DateWritten>
private bool PutServerOnline()
{
#region//Set up local variables TT\\
bool bolSuccess = false;
#endregion
#region//Try and start the server TT\\
try
{
//Set IP Address TT\\
IPAddress ipAddr = IPAddress.Parse(Functions.GetIPAddress());
//Start the Server TT\\
_Server Server = new _Server(ipAddr);
_Server.StatusChanged += new StatusChangedEventHandler(Server_StatusChanged);
Server.StartListening();
//Inform the program and the user that the server is online TT\\
txtRaw.AppendText("The server is now online and accepting messages on " + ipAddr + " \r\n");
bolSuccess = true;
}
#endregion
#region//If the server didn't start TT\\
catch
{
//The server did not succesfully start TT\\
bolSuccess = false;
}
#endregion
#region//Check if the server has successfuly been put online TT\\
if (bolSuccess)
{
//Add a test message\\
//Set the display to show the server is online TT\\
this.Text = _strProgramName + " - Online";
cmdStatus.Visible = false;
lblStatus.Left = cmdStatus.Left;
lblStatus.Text = _strOnlineLabel + Functions.GetIPAddress();
//Set the Online variable to false TT\\
bolOnline = true;
}
#endregion
#region//Return the outcome TT\\
return bolSuccess;
#endregion
}
public void Server_StatusChanged(object sender, StatusChangedEventArgs e)
{
// Call the method that updates the form
try
{
this.Invoke(new UpdateStatusCallback(this.UpdateStatus), new object[] { e.EventMessage });
}
catch
{
}
}
/// <summary>
/// Adds the message to the raw if required
/// </summary>
/// <param name="strMessage"></param>
/// <AuthorName>TT</AuthorName>
/// <DateWritten>09/04/2009</DateWritten>
private void UpdateStatus(string strMessage)
{
//Check if raw data is requested TT\\
if (chkRaw.Checked == true)
{
//Add the raw message to the raw data box TT\\
txtRaw.AppendText(strMessage + "\r\n");
strMessage = null;
}
}
#endregion
public void AddUser(string Name)
{
//Add the user onto the
lstUsers.Items.Add(Name);
lstUsers.Refresh();
}
public void RemoveUser(string Name)
{
try
{
lstUsers.Items.Remove(Name);
}
catch
{
MessageBox.Show("ERRROR");
}
}
public void AppendRaw(string Message)
{
if (bolRaw)
{
txtRaw.AppendText(Message);
}
}
private void chkRaw_CheckedChanged(object sender, EventArgs e)
{
bolRaw = chkRaw.Checked;
}
private void cmdSend_Click(object sender, EventArgs e)
{
_Server.SendMessage("This is a single user test", "Tom Turner");
}
}
}ASKER
The server.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Threading;
using System.Collections;
namespace STD_Server
{
#region// Holds the arguments for the StatusChanged event - Needs to be commented
public class StatusChangedEventArgs : EventArgs
{
// The argument we're interested in is a message describing the event
private string EventMsg;
// Property for retrieving and setting the event message
public string EventMessage
{
get
{
return EventMsg;
}
set
{
EventMsg = value;
}
}
// Constructor for setting the event message
public StatusChangedEventArgs(string strEventMsg)
{
frmMain Main = new frmMain();
if (Main.bolRaw)
{
Main.AppendRaw(strEventMsg);
}
EventMsg = strEventMsg;
}
}
#endregion
// This delegate is needed to specify the parameters we're passing with our event
public delegate void StatusChangedEventHandler(object sender, StatusChangedEventArgs e);
class _Server
{
#region//Variables and arrays\\
//Set the Hash tables to store users and connections TT\\
public static Hashtable htUsers = new Hashtable(frmMain._intMaxUsers);
public static Hashtable htConnections = new Hashtable(frmMain._intMaxUsers);
// Will store the IP address passed to it
private IPAddress ipAddress;
private TcpClient tcpClient;
// The event and its argument will notify the form when a user has connected, disconnected, send message, etc.
public static event StatusChangedEventHandler StatusChanged;
private static StatusChangedEventArgs e;
// The thread that will hold the connection listener
private Thread thrListener;
// The TCP object that listens for connections
private TcpListener tlsClient;
// Will tell the while loop to keep monitoring for connections
bool ServRunning = false;
#endregion
/// <summary>
/// This sets the IP Address
/// </summary>
/// <param name="address"></param>
public _Server(IPAddress address)
{
ipAddress = address;
}
/// <summary>
/// Add the user to the hash tables
/// </summary>
/// <param name="tcpUser"></param>
/// <param name="strUsername"></param>
public static void AddUser(TcpClient tcpUser, string strUsername)
{
//Allow a connection to the add user function on the main form\\
frmMain MainForm = new frmMain();
// First add the username and associated connection to both hash tables
_Server.htUsers.Add(strUsername, tcpUser);
_Server.htConnections.Add(tcpUser, strUsername);
MainForm.AddUser(htConnections[tcpUser].ToString());
// Tell of the new connection to all other users and to the server form
SendMessage(htConnections[tcpUser] + " has joined us", null);
}
/// <summary>
/// Remove the user from the hash tables
/// </summary>
/// <param name="tcpUser"></param>
public static void RemoveUser(TcpClient tcpUser)
{
// If the user is there
if (htConnections[tcpUser] != null)
{
string name = htConnections[tcpUser].ToString();
// Remove the user from the hash table
_Server.htUsers.Remove(_Server.htConnections[tcpUser]);
_Server.htConnections.Remove(tcpUser);
// First show the information and tell the other users about the disconnection
SendMessage("Admin", name + " has left us");
}
}
/// <summary>
/// This is called when we want to raise the StatusChanged event
/// </summary>
/// <param name="e"></param>
public static void OnStatusChanged(StatusChangedEventArgs e)
{
StatusChangedEventHandler statusHandler = StatusChanged;
if (statusHandler != null)
{
// Invoke the delegate
statusHandler(null, e);
}
}
/// <summary>
/// Send a message to all users
/// </summary>
/// <param name="From"></param>
/// <param name="Message"></param>
public static void SendMessage(string Message, string To)
{
//Set up the stream writter TT\\
StreamWriter swSender;
//Update the Raw log TT\\
e = new StatusChangedEventArgs(Message);
OnStatusChanged(e);
//Create an array of users as this can be accessed more easily TT\\
TcpClient[] tcpClients = new TcpClient[_Server.htUsers.Count];
//Copy the user list into the new array TT\\
_Server.htUsers.Values.CopyTo(tcpClients, 0);
//Loop through the list of users TT\\
for (int i = 0; i < tcpClients.Length; i++)
{
//Try to send a message to the user TT\\
try
{
//Check the is not null and the client exists TT\\
if (Message.Trim() == "" ||
tcpClients[i] == null)
{
continue;
}
//If no specific user has been selected or the to is selected TT\\
if (To == null ||
To == tcpClients[i].ToString())
{
//Send the message to the current user TT\\
swSender = new StreamWriter(tcpClients[i].GetStream());
swSender.WriteLine(Message);
swSender.Flush();
}
}
//If there has been an error remove the user TT\\
catch
{
RemoveUser(tcpClients[i]);
}
}
}
public void StartListening()
{
// Get the IP of the first network device, however this can prove unreliable on certain configurations
IPAddress ipaLocal = ipAddress;
// Create the TCP listener object using the IP of the server and the specified port
tlsClient = new TcpListener(ipAddress, 1986);
// Start the TCP listener and listen for connections
tlsClient.Start();
// The while loop will check for true in this before checking for connections
ServRunning = true;
// Start the new tread that hosts the listener
thrListener = new Thread(KeepListening);
thrListener.Start();
}
private void KeepListening()
{
// While the server is running
while (ServRunning == true)
{
// Accept a pending connection
tcpClient = tlsClient.AcceptTcpClient();
// Create a new instance of Connection
Connection newConnection = new Connection(tcpClient);
}
}
}
#region//Connection\\
/// <summary>
/// Handels connections,
/// Each user will have a connection of there own
/// </summary>
class Connection
{
TcpClient tcpClient;
// The thread that will send information to the client
private Thread thrSender;
private StreamReader srReceiver;
private StreamWriter swSender;
private string currUser;
private string strResponse;
// The constructor of the class takes in a TCP connection
public Connection(TcpClient tcpCon)
{
tcpClient = tcpCon;
// The thread that accepts the client and awaits messages
thrSender = new Thread(AcceptClient);
// The thread calls the AcceptClient() method
thrSender.Start();
}
private void CloseConnection()
{
// Close the currently open objects
tcpClient.Close();
srReceiver.Close();
swSender.Close();
}
// Occures when a new client is accepted
private void AcceptClient()
{
srReceiver = new System.IO.StreamReader(tcpClient.GetStream());
swSender = new System.IO.StreamWriter(tcpClient.GetStream());
// Read the account information from the client
currUser = srReceiver.ReadLine();
// We got a response from the client
if (currUser != "")
{
// Store the user name in the hash table
if (_Server.htUsers.Contains(currUser) == true)
{
// 0 means not connected
swSender.WriteLine("0|This username already exists.");
swSender.Flush();
CloseConnection();
return;
}
else if (currUser == "Administrator")
{
// 0 means not connected
swSender.WriteLine("0|This username is reserved.");
swSender.Flush();
CloseConnection();
return;
}
else
{
// 1 means connected successfully
swSender.WriteLine("1");
swSender.Flush();
// Add the user to the hash tables and start listening for messages from him
_Server.AddUser(tcpClient, currUser);
}
}
else
{
CloseConnection();
return;
}
try
{
// Keep waiting for a message from the user
while ((strResponse = srReceiver.ReadLine()) != "")
{
// If it's invalid, remove the user
if (strResponse == null)
{
_Server.RemoveUser(tcpClient);
}
else
{
// Otherwise send the message to all the other users
_Server.SendMessage(strResponse, null);
}
}
}
catch
{
// If anything went wrong with this user, disconnect him
_Server.RemoveUser(tcpClient);
}
}
}
#endregion
}ASKER
The functions class
ASKER
woops forgot to add the code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace STD_Server
{
class Functions
{
/// <summary>
/// Converts a string to MD5
/// </summary>
/// <param name="input"></param>
/// <returns>MD5 String</returns>
/// http://blog.brezovsky.net/en-text-2.html
public static string MD5(string input)
{
System.Security.Cryptography.MD5CryptoServiceProvider MD5Convert = new System.Security.Cryptography.MD5CryptoServiceProvider();
byte[] bs = System.Text.Encoding.UTF8.GetBytes(input);
bs = MD5Convert.ComputeHash(bs);
System.Text.StringBuilder s = new System.Text.StringBuilder();
foreach (byte b in bs)
{
s.Append(b.ToString("x2").ToLower());
}
string output = s.ToString();
return output;
}
/// <summary>
/// Get the Computers IP Address
/// </summary>
/// <returns>IP Address</returns>
public static string GetIPAddress()
{
//Loop Back\\
return "127.0.0.1";
//return "169.254.154.235";
}
}
}ASKER
and if you need it, the form design
namespace STD_Server
{
partial class frmMain
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.cmdStatus = new System.Windows.Forms.Button();
this.lblStatus = new System.Windows.Forms.Label();
this.txtRaw = new System.Windows.Forms.TextBox();
this.chkRaw = new System.Windows.Forms.CheckBox();
this.lstUsers = new System.Windows.Forms.ListBox();
this.cmdKick = new System.Windows.Forms.Button();
this.cmdSend = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// cmdStatus
//
this.cmdStatus.Location = new System.Drawing.Point(11, 8);
this.cmdStatus.Name = "cmdStatus";
this.cmdStatus.Size = new System.Drawing.Size(104, 22);
this.cmdStatus.TabIndex = 0;
this.cmdStatus.Text = "Put Server Online";
this.cmdStatus.UseVisualStyleBackColor = true;
this.cmdStatus.Click += new System.EventHandler(this.cmdStatus_Click);
//
// lblStatus
//
this.lblStatus.AutoSize = true;
this.lblStatus.Location = new System.Drawing.Point(121, 17);
this.lblStatus.Name = "lblStatus";
this.lblStatus.Size = new System.Drawing.Size(103, 13);
this.lblStatus.TabIndex = 1;
this.lblStatus.Text = "The Server is Offline";
//
// txtRaw
//
this.txtRaw.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right)));
this.txtRaw.Location = new System.Drawing.Point(11, 409);
this.txtRaw.Multiline = true;
this.txtRaw.Name = "txtRaw";
this.txtRaw.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
this.txtRaw.Size = new System.Drawing.Size(494, 114);
this.txtRaw.TabIndex = 2;
//
// chkRaw
//
this.chkRaw.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
this.chkRaw.AutoSize = true;
this.chkRaw.Location = new System.Drawing.Point(11, 386);
this.chkRaw.Name = "chkRaw";
this.chkRaw.Size = new System.Drawing.Size(104, 17);
this.chkRaw.TabIndex = 3;
this.chkRaw.Text = "Show Raw Data";
this.chkRaw.UseVisualStyleBackColor = true;
this.chkRaw.CheckedChanged += new System.EventHandler(this.chkRaw_CheckedChanged);
//
// lstUsers
//
this.lstUsers.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)));
this.lstUsers.FormattingEnabled = true;
this.lstUsers.Location = new System.Drawing.Point(11, 40);
this.lstUsers.Name = "lstUsers";
this.lstUsers.Size = new System.Drawing.Size(161, 342);
this.lstUsers.TabIndex = 4;
//
// cmdKick
//
this.cmdKick.Location = new System.Drawing.Point(178, 72);
this.cmdKick.Name = "cmdKick";
this.cmdKick.Size = new System.Drawing.Size(93, 26);
this.cmdKick.TabIndex = 5;
this.cmdKick.Text = "Kick User";
this.cmdKick.UseVisualStyleBackColor = true;
//
// cmdSend
//
this.cmdSend.Location = new System.Drawing.Point(178, 40);
this.cmdSend.Name = "cmdSend";
this.cmdSend.Size = new System.Drawing.Size(93, 26);
this.cmdSend.TabIndex = 6;
this.cmdSend.Text = "Send Message";
this.cmdSend.UseVisualStyleBackColor = true;
this.cmdSend.Click += new System.EventHandler(this.cmdSend_Click);
//
// frmMain
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(517, 535);
this.Controls.Add(this.cmdSend);
this.Controls.Add(this.cmdKick);
this.Controls.Add(this.lstUsers);
this.Controls.Add(this.chkRaw);
this.Controls.Add(this.txtRaw);
this.Controls.Add(this.lblStatus);
this.Controls.Add(this.cmdStatus);
this.Name = "frmMain";
this.Text = "ServerTransmitted Data - Offline";
this.Load += new System.EventHandler(this.frmMain_Load);
this.ResumeLayout(false);
this.PerformLayout();
}
#endregion
private System.Windows.Forms.Button cmdStatus;
private System.Windows.Forms.Label lblStatus;
private System.Windows.Forms.TextBox txtRaw;
private System.Windows.Forms.CheckBox chkRaw;
private System.Windows.Forms.ListBox lstUsers;
private System.Windows.Forms.Button cmdKick;
private System.Windows.Forms.Button cmdSend;
}
}ASKER CERTIFIED SOLUTION
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btw nice code... and a lot of comments :)
i'm a little bit lazy
can you put your app.. or example app with this on upload site..
can you put your app.. or example app with this on upload site..
ASKER
this is the client http://www.host2trust.co.uk/ChatClient.exe
and this is the server files http://host2trust.co.uk/STD-Server.zip
and this is the server files http://host2trust.co.uk/STD-Server.zip
The requested URL /STD-Server.zip was not found on this server.
ASKER
Woops, it was the making a new form i had run the code on the new unshown form, once i showed it, it worked
> I have tryed a this.refresh, lstItems.Update(), lstItems.Refresh() all dont work
Where you did this.refresh, lstItems.Update(), lstItems.Refresh()
> I have tryed a this.refresh, lstItems.Update(), lstItems.Refresh() all dont work
you meant lstItems.Refresh not this.refresh right ?