Почему не меняется label? - C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
 
namespace Ex._5
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            int count = 0, n, x, sum;
            n = Convert.ToInt32(textBox1.Text);
            while (n > 0)
            {
                x = n % 10;
                sum = n / 10;
                if (x != 0)
                {
                    count++;
                }
 
            }
            label2.Text = count.ToString();
        }
    }
}