Evento KeyUp

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;

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

        private void textBox1_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.KeyValue == 13)
                MessageBox.Show("Se ha pulsado la tecla Enter");
        }




        private void Salir(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}