Clear listView except View C#

Hi,

I have a listView with results of a scan. I've used three culomns in the listView. 

When I press the button 'Clear Items' (button 5) I want that only the results will be cleared, not the columns.

My code is:

private void button5_Click(object sender, EventArgs e)
        {
            listView1.Clear();
        }

Can anyone help me?