UpdateProgressBarOnThread.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Threading;


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

        int val = 1;
        Thread thread;
        private void btnStart_Click(object sender, EventArgs e)
        {
            thread = new Thread(new ThreadStart(UpdatePB));
            thread.Start();
        }

        private void UpdatePB()
        {
            while (true)
            {
                if (val >= 99) val = 1;
                UpdateProgress(val++);
                Thread.Sleep(50);
            }
        }

        private void UpdateProgress(int val)
        {
            if (pbProgress.InvokeRequired)
            {
                pbProgress.Invoke(new Action(() => UpdateProgress(val)));
            } else
            {
                pbProgress.Value = val;
            }
        }

        private void btnStop_Click(object sender, EventArgs e)
        {
            if (thread != null)
            {
                thread.Abort();
            }
        }
    }
}