At first Excuse me for asking this question.

I have just entered in topic of Threads and I’m beginner in this topic.
I have a problem with my program in runtime like this:

“Cross-thread operation not valid: Control ‘listBox1’ accessed from a thread other than the thread it was created on.”

I think my program is very very simple. But it has errors.
Please help me!
Thanks!

I expect the program that when I click the button1, it will adds some numbers with sum strings in the listBox1.
I declare a for loop that iterates from 0 to 9.

The error message is above and my very simple codes are below:

type 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;

namespace Threads_01
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        System.Threading.Thread Thread_01;

        private void button1_Click(object sender, EventArgs e)
        {

            Thread_01.Start();
          

        }

        private void function_01()
        {
            string item;

            for (int i = 0; i < 10; i++)
            {
                item = "Hello abc (" + i.ToString() + ")";

                listBox1.Items.Add(item);    
            }

            
        }

        private void Form1_Load(object sender, EventArgs e)
        {
           

            //Thread_01 = new System.Threading.Thread(function_01, 10);

            Thread_01 = new System.Threading.Thread(function_01);
        }
    }
}

//Those are the codes of file: “Form1.cs”.
//and the designer codes are:

namespace Threads_01
{
    partial class Form1
    {
        /// <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.button1 = new System.Windows.Forms.Button();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(44, 36);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(102, 48);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // listBox1
            // 
            this.listBox1.FormattingEnabled = true;
            this.listBox1.Location = new System.Drawing.Point(44, 116);
            this.listBox1.Name = "listBox1";
            this.listBox1.Size = new System.Drawing.Size(225, 277);
            this.listBox1.TabIndex = 1;
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(683, 447);
            this.Controls.Add(this.listBox1);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.ListBox listBox1;
    }
}

//and the program.cs codes are:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace Threads_01
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}