C# TextBox LostFocus找不到

在vs里面选择TextBox在事件栏里面是找不到LostFocus事件的，但是在代码里面可以找到 

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 Test210825
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            textBox1.LostFocus += TextBox1_LostFocus;
        }
        int i = 0;
       

        private void TextBox1_LostFocus(object sender, EventArgs e)
        {
            i++;
            textBox2.Text = i.ToString();
        }

        private void textBox1_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                TextBox1_LostFocus(sender, e);
            }
        }
    }
}