Multithreading in C#

public partial class Form1 : Form
    {
        Thread threadObj;
        public delegate void delename();
        
        public bool stopProcess = false;
 
        public Form1()
        {
            InitializeComponent();          
        }

        private void Start_Btn_Click(object sender, EventArgs e)
        {
            this.stopProcess = false;
            threadObj = new Thread(new ThreadStart(ThreadStartNow));
            threadObj.Start();
        }

        private void Stop_Btn_Click(object sender, EventArgs e)
        {
            this.stopProcess = true;             
        }
        
        public void ThreadStartNow()
        {
            if (!this.stopProcess)
            {
                this.BeginInvoke(new delename(Method1));
            }
            else
            {
                this.threadObj.Abort();
            }
        }
        public void Method1()
        {
            
                    for (int i = 0; i <= 50; i++)
                    {
                        textBox1.Text = i.ToString();
                        Thread.Sleep(500);
                        textBox1.Refresh();
                    }
  
        }

    }