When I run the program I get an exception on line 54:
Cross-thread operation not valid: Control 'listBoxResult' accessed from a thread other than the thread it was created on.
Form:
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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.Threading;
//-------
using System.Net;
using System.Net.Sockets;
//------
namespace ThreadDemo
{
public partial class MainForm : Form
{
ChatClient cl;
Thread updateThread;
public MainForm()
{
InitializeComponent();
}
private void startButton_Click(object sender, EventArgs e)
{
cl = new ChatClient();
// Register event handlers.
cl.ListenModeOutput += updateTextBox;
ThreadStart startFunc = new ThreadStart(cl.listenMode);
updateThread = new Thread(startFunc);
updateThread.Start();
}
private void stopButton_Click(object sender, EventArgs e)
{
//threadDone = true;
}
//target for event
private void updateTextBox(String str)
{
listBoxResult.Items.Add(str);
}
private void MainForm_Load(object sender, EventArgs e)
{
}
}
}Client.cs
-----------------------------------------
//what kind of exceptions might happen
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Threading;
namespace ThreadDemo
{
class ChatClient
{
TcpClient client;
NetworkStream stream;
//a delegate that poins to a function that return void
//and takes one argument
public delegate void OutputHandler(String msg);
//client can send this event
public event OutputHandler ListenModeOutput;
public ChatClient()
{
client = new TcpClient();
client.Connect("localhost", 1234);
Console.WriteLine("connected to server!");
stream = client.GetStream();
}
public void listenMode()
{
int i = Thread.CurrentThread.ManagedThreadId;
ListenModeOutput("listening....");
while (true)
{
while (stream.DataAvailable)
{
byte[] inbuffer = new byte[256];
int numBytesRead = stream.Read(inbuffer, 0, inbuffer.Length);
string inmsg = Encoding.ASCII.GetString(inbuffer, 0, numBytesRead);
ListenModeOutput("Server:" + inmsg);
}
}
}
}
}