城杆

private void button1_Click(object sender, EventArgs e)
        {
            Thread thread = new Thread(new ThreadStart(DoWork));
            thread.Start();
            button1.Enabled = false;
        }

        private void AA()
        {
            button1.Enabled = true;
        }

        private void DoWork()
        {
            double sum = 0;
            for (int i = 0; i < 100000; i++)
            {
                sum += i;
            }

            MessageBox.Show(sum.ToString());
            this.Invoke(new Action(AA));
        }