WinForm ListBox MultiColumn

NOTE:-

NOTE:-

NOTE:-

CODE:

using System;
using System.Windows.Forms;

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

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void LaodButton_Click(object sender, EventArgs e)
        {
            ListBox1.Items.Clear();
            ListBox1.MultiColumn = MultiColumnCheckBox.Checked;
            if (NumTextBox.Text.Trim() != string.Empty)
            {
                bool success = Int32.TryParse(NumTextBox.Text.Trim(), out int num);
                if (success)
                {
                    int result;
                    for (int i = 1; i <= 100; i++)
                    {
                        result = i * num;
                        string mult = string.Format("{0} * {1} = {2}", i, num, result);
                        ListBox1.Items.Add(mult);
                    }

                }
                else
                {
                    MessageBox.Show("Please enter a valid number.", "Required", MessageBoxButtons.OK);
                    NumTextBox.Focus();
                }
            }
            else
            {
                MessageBox.Show("Please enter a number.", "Required", MessageBoxButtons.OK);
                NumTextBox.Focus();
            }
        }
    }
}