Input a string in a Textbox and it Reverse string in C#

Input a string in a textbox and reverse the string to display it in another textbox

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 Reverse

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

//Using  by  for loop............................

char[] ch;

        private void btnByForLoop_Click(object sender, EventArgs e)

        {

            string ch = txtinputstring.Text;

            txtoutputstring.Text = string.Empty;

            for (int i = ch.Length - 1; i >= 0; i--)

            {

                txtoutputstring.Text += ch[i].ToString();

            }

        }
               

//Using  by  function ............................

        public string myrev(char[] val)

        {

            string total = string.Empty;

            for (int i = val.Length - 1; i >= 0; i--)

            {

                total += val[i].ToString();

            }

            return total;

        }

        private void BtnByFun_Click(object sender, EventArgs e)

        {

            string val = txtinputstring.Text;

            txtoutputstring.Text = myrev(val.ToCharArray());

        }

//Using  by ForEach Loop function ............................

        private void btnForEach_Click(object sender, EventArgs e)

        {

            foreach (char c in txtinputstring.Text.ToCharArray())

            {

                txtoutputstring.Text = c + txtoutputstring.Text;

            }

        }

    }

}