Questo codice seguente mi dà l'errore qui sotto. Penso di aver bisogno di "InvokeRequired". Ma non capisco come posso usare?Come posso correggere l'errore "accesso da un thread diverso dal thread su cui è stato creato"?
Operazione cross-thread non valida: controllo 'elencoBox1' a cui si accede da un thread diverso dal thread su cui è stato creato.
Il codice:
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;
namespace WindowsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
protected static DataSet dataset = null;
private void Form1_Load(object sender, EventArgs e)
{
}
private void timer1_Tick(object sender, EventArgs e)
{
SimulationFrameWork.MCSDirector run = new SimulationFrameWork.MCSDirector();
DataSet ds = run.Get();
if (ds.Tables[0].Rows.Count > 0)
{
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
if (ds.Tables[0].Rows[i]["result"].ToString() == "0")
{
dataset = run.Get(int.Parse(ds.Tables[0].Rows[i]["ID"].ToString()));
WorkerObject worker =
new WorkerObject(
int.Parse(dataset.Tables[0].Rows[i]["ID"].ToString()),
int.Parse(dataset.Tables[0].Rows[i]["Iteration"].ToString()),
listBox1, timer1);
Thread thread1 = new Thread(new ThreadStart(worker.start));
thread1.Start();
}
}
}
}
}
public class WorkerObject
{
private int id;
private int nmax;
private ListBox list1;
private System.Windows.Forms.Timer timer1;
public WorkerObject(int _id, int _nmax, ListBox _list1,
System.Windows.Forms.Timer _timer1)
{
id = _id;
nmax = _nmax;
list1 = _list1;
timer1 = _timer1;
}
public void start()
{
timer1.Stop();
int i, idaire, j;
double pi = 0.0, x, y;
Random rnd = new Random();
for (i = 0; i < 100; i++)
{
idaire = 0;
for (j = 0; j < nmax; j++)
{
x = rnd.Next(1, 10000)/(double)10000;
y = rnd.Next(1, 10000)/(double)10000;
if (Math.Pow(x, 2) + Math.Pow(y, 2) <= 1.0)
idaire += 1;
}
pi = 4 * (double)idaire/(double)nmax;
nmax *= 10;
list1.Items.Add(
"Iterasyon:" +
nmax.ToString() +
" ----->" +
pi.ToString() +
"\n");
System.Threading.Thread.Sleep(100);
}
SimulationFrameWork.MCSDirector run = new SimulationFrameWork.MCSDirector();
run.Update(id, pi);
list1.Items.Add("\n\n islem bitti...");
}
}
}
Verificate anche questa soluzione sul problema; uno molto elegante: http://stackoverflow.com/questions/906057/problem-with-delegate-syntax-in-c/906097#906097 –