How to clear a Multiple TextBox values in a single click in C# .NET

public static class ControlExtension
 {
   public static IList<t> FindControlByName<t>(this Control control) where T : Control
   {
     List<t> controlsFound = new List<t>();

     controlsFound.AddRange(control.Controls.OfType<t>());
     foreach (Control c in control.Controls)
     {
       controlsFound.AddRange(FindControlByName<t>(c));
     }
     return controlsFound;
   }
 }

this.FindControlByName<textbox>().ToList().ForEach(t => t.Clear());