virtual keyboard in C#

//Add a user control in the project and write the code below.
//Create all buttons on the control and make same event (Click Event) for all the buttons except 3 buttons (like backspace,clear and caps lock)


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Forms;


namespace Virtual_KeyBoard
{
    public partial class ucKeyboard : UserControl
    {

        public Form1 frmLogin = null;
        Random rnd = new Random();
        Button[] numericButtons = new Button[10];
        Button[] alphaButtons = new Button[36];

        public ucKeyboard()
        {
            InitializeComponent();
        }
        public bool Flag = false; int i = 0;

        public void NumericButtonLocation()
        {
          foreach (Control ctrl in this.Controls)
          {
              if (ctrl is Button && ctrl.TabIndex <10)
              {
                  if (ctrl.Text != "Caps Lock" && ctrl.Text != "BackSpace" && ctrl.Text != "Clear")
                  numericButtons[ctrl.TabIndex] = ctrl as Button;
              }
          }
          for (int j = 0; j < 9; j++)
          {
              int selectedButtonIndex = rnd.Next(1,9);
              int next = rnd.Next(1, 9);
              swapNumeric(selectedButtonIndex, next);

          }
        }
        private void swapNumeric(int btn1X, int btn1Y)
        {
            string temp = numericButtons[btn1X].Text;

            numericButtons[btn1X].Text = numericButtons[btn1Y].Text;
            numericButtons[btn1Y].Text = temp;
        }
        private void swapAlphabets(int btn1, int btn2)
        {
            string temp = alphaButtons[btn1].Text;

            alphaButtons[btn1].Text = alphaButtons[btn2].Text;
            alphaButtons[btn2].Text = temp;
        }
        public void AlphabetButtonLocation()
        {
             foreach (Control ctrl in this.Controls)
            {
                if (ctrl is Button && ctrl.TabIndex >10 && ctrl.TabIndex < 36)
                {
                    alphaButtons[ctrl.TabIndex] = ctrl as Button;
                  
                }
            }
            for (int j = 0; j < 27; j++)
            {
                int selectedButtonIndex = rnd.Next(11, 35);
                int next = rnd.Next(11, 35);
                swapAlphabets(selectedButtonIndex, next);

            }
        }



        private void button_clear_Click(object sender, EventArgs e)
        {
            frmLogin.nVirtualBox.Text = string.Empty;
        }

        private void button_backspace_Click(object sender, EventArgs e)
        {
            if (frmLogin.nVirtualBox.Text != "")
                frmLogin.nVirtualBox.Text = frmLogin.nVirtualBox.Text.Remove(frmLogin.nVirtualBox.Text.Length - 1, 1);
            else
                return;
         }

       
        private void btnVirtualKey_Click(object sender, EventArgs e)
        {
            Button b = sender as Button;
            if (!Flag)
            {
                frmLogin.display(b.Text.ToLower());
            }
            else
            {
                frmLogin.display(b.Text.ToUpper());
            }
        }

        private void btnCapsLock_Click(object sender, EventArgs e)
        {
            if (i == 0)
            {
                Flag = true;
                i++;
                for (int j = 0; j < this.Controls.Count; j++)
                {
                    Control ctl = (Button)this.Controls[j];
                    if (ctl != btnCapsLock && ctl != button_backspace && ctl != button_clear)
                    {
                        this.Controls[j].Text = this.Controls[j].Text.ToUpper();
                    }
                }
            }
            else
            {
                i = 0;
                Flag = false;
                for (int j = 0; j < this.Controls.Count; j++)
                {
                    Control ctl = (Button)this.Controls[j];
                    if (ctl != btnCapsLock && ctl != button_backspace && ctl != button_clear)
                    {
                        this.Controls[j].Text = this.Controls[j].Text.ToLower();
                    }
                }
            }
        }

        private void ucKeyboard_Load(object sender, EventArgs e)
        {
            NumericButtonLocation();
            AlphabetButtonLocation();
        }
    }
}
// Now in the form (Form1) put the code below



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 Virtual_KeyBoard
{
    public partial class Form1 : Form
    {
        public static Form1 frm = null;
        public TextBox nVirtualBox;
       
        //Creat instance of form if no one is created otherwise set that instance available.
        public Form1 getreference()
        {
            if (frm == null)
                frm = new Form1();
            return this;
        }
        public Form1()
        {
            InitializeComponent();
        }

//set a virtualTextbox for any of the selected textbox on runtime.
        public void display(string str)
        {
            if (nVirtualBox != null)
            {
                nVirtualBox.Text += str;
            }
        }

        // To load again the new keyboard with different locations of all buttons.
        // it will attached with the uckeyboard load event.
        private void ucKeyboard1_Load(object sender, EventArgs e)
        {
            ucKeyboard1.NumericButtonLocation();
            ucKeyboard1.AlphabetButtonLocation();
            this.ucKeyboard1.frmLogin = this;
        }

        private void txtboxfirst_Enter(object sender, EventArgs e)
        {
            nVirtualBox = sender as TextBox;
            if (nVirtualBox == null)
                nVirtualBox = txtboxfirst;
        }

      
        private void ucKeyboard1_Load_1(object sender, EventArgs e)
        {
            this.ucKeyboard1.frmLogin = this;
        }      

       
    }
}