Effacer contenu d’un dataGridView

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.Diagnostics;
 

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            dataGridView1.ColumnCount = 3; // ajouter 3 colonnes afin de placer les lignes dans chaque colonnes 
            dataGridView1.Columns[0].Name = "Colonne 1"; // colonne 1
            dataGridView1.Columns[1].Name = "Colonne 2"; // colonne 2
            dataGridView1.Columns[2].Name = "Colonne 3"; // colonne 3
        }

        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            dataGridView1.Columns.Clear(); // effacer - clear            

        }
    }
}