C# -- listbox 에서 선택해제하기 (deselect)

listbox_deselect.cs

using System;
using System.Windows.Forms;

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

            this.listBox1.Items.Add(1);
            this.listBox1.Items.Add(2);
            this.listBox1.Items.Add(566);
            this.listBox1.Items.Add("test");
            this.listBox1.Items.Add(5);
            this.listBox1.Items.Add(337);
            this.listBox1.Items.Add(64);
            this.listBox1.Items.Add(7);
        }

        private void buttonSelect_Click(object sender, EventArgs e)
        {
            //this.listBox1.SelectionMode = SelectionMode.One;

            this.listBox1.SelectedIndex = 2;
        }

        private void buttonDeselect_Click(object sender, EventArgs e)
        {
            //this.listBox1.SelectionMode = SelectionMode.None;

            //this.listBox1.SelectedItem = null;
            //this.listBox1.SelectedIndex = -1;

            this.listBox1.BeginInvoke(new Action(() =>
            {
                //this.listBox1.SelectedItem = null;
                this.listBox1.SelectedIndex = -1;
            }));
        }
    }
}