Formatowanie textu

form1.cs

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 WindowsFormsApp2
{


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

        public static class FormInputHelper
        {
            public static char[] trimmers = { '-' };
            
            public static string FilterName(string input)
            {
                input = input
                    .Trim()
                    .Trim(trimmers)
                    .Trim('-');
                input = FilterForbiddenChars(input);

                return input;
            }
            
            public static string FilterForbiddenChars(string input)
            {
                var forbiddenChars = new string[] { "@", ",", ".", ";", "'", "&", "$", "{", "}" };//to extend
                foreach (var f in forbiddenChars)
                {
                    input = input.Replace(f, string.Empty);
                }
                return input;
            }
        }
        
        private void button1_Click(object sender, EventArgs e)
        {

            var input = FormInputHelper.FilterName(textBox1.Text);
            label1.Text = input;
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (char.IsLetter(e.KeyChar) || char.IsControl(e.KeyChar) || char.IsPunctuation(e.KeyChar))
            {
                return;
            }
            e.Handled = true;
        }
    }
}