Select All

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

namespace SelectAlll
{
    public partial class SelectAll: UserControl
    {
        public SelectAll()
        {
            InitializeComponent();
        }

        public List<string> Estados = new List<string>();
        private void SelectAll_Load(object sender, EventArgs e)
        {

        }

        public void Deschequear()
        {
            chk.Checked = false;
        }

        private void chk_CheckedChanged(object sender, EventArgs e)
        {
            foreach (Control r in this.ParentForm.Controls)
            {
                if (r is CheckBox)
                {

                    if(((CheckBox)r).Checked == false )
                    {
                        Graphics g = this.ParentForm.CreateGraphics();

                        int x = r.Location.X;
                        int y = r.Location.Y;
                        int ancho = r.Size.Height;
                        int largo = r.Size.Width;

                        g.DrawRectangle(Pens.Blue, x - 2, y - 2, largo + 2, ancho + 2);

                    }




                   if (chk.Checked == true)
                    {
                        Estados.Add(((CheckBox)r).Name.ToString() + ','+((CheckBox)r).Checked.ToString());
                        ((CheckBox)r).Checked = true;
                    }

                   if (chk.Checked == false)
                    {
                        foreach (string s in Estados)
                        {
                            string[] chkestados = s.Split(',');
                            if ( ((CheckBox)r).Name == chkestados[0])
                            {
                                ((CheckBox)r).Checked = bool.Parse(chkestados[1]);

                                if (((CheckBox)r).Checked == false)
                                {

                                    Graphics g = this.ParentForm.CreateGraphics();
                                    Pen p = new Pen(this.ParentForm.BackColor);
                                    int x = r.Location.X;
                                    int y = r.Location.Y;
                                    int ancho = r.Size.Height;
                                    int largo = r.Size.Width;

                                    g.DrawRectangle(p, x - 2, y - 2, largo + 2, ancho + 2);

                                }

                            }
                        }
                    }

                }
            }
        }
    }
}