как остановить мерцание C # winforms

У меня есть программа, которая по сути похожа на приложение для рисования. Однако у моей программы есть проблемы с мерцанием. У меня есть следующая строка в моем коде (которая должна избавить от мерцания, но этого не происходит):

this.SetStyle(ControlStyles.AllPaintingInWmPaint 
| ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true);

мой код (без суперклассов и подклассов для фигур выглядит следующим образом:

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 Paint
{
    public partial class Paint : Form
    {
        private Point startPoint;
        private Point endPoint;
        private Rectangle rect = new Rectangle();
        private Int32 brushThickness = 0;
        private Boolean drawSPaint = false;
        private List<Shapes> listOfShapes = new List<Shapes>();
        private Color currentColor;
        private Color currentBoarderColor;
        private Boolean IsShapeRectangle = false;
        private Boolean IsShapeCircle = false;
        private Boolean IsShapeLine = false;

        public SPaint()
        {

            InitializeComponent();
            this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true);

            currentColor = Color.Red;
            currentBoarderColor = Color.DodgerBlue;
            IsShapeRectangle = true; 
        }

        private void panelArea_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = panelArea.CreateGraphics();

            if (drawSPaint == true)
            {

                Pen p = new Pen(Color.Blue);
                p.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;

                if (IsShapeRectangle == true)
                {
                    g.DrawRectangle(p, rect);
                }
                else if (IsShapeCircle == true)
                {
                    g.DrawEllipse(p, rect);
                }
                else if (IsShapeLine == true)
                {
                    g.DrawLine(p, startPoint, endPoint);
                }
            }
            foreach (Shapes shape in listOfShapes)
            {

                shape.Draw(g);

            }
        }

        private void panelArea_MouseDown(object sender, MouseEventArgs e)
        {

            startPoint.X = e.X;
            startPoint.Y = e.Y;

            drawSPaint = true;
        }

        private void panelArea_MouseMove(object sender, MouseEventArgs e)
        {


            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {

                if (e.X > startPoint.X)
                {
                    rect.X = startPoint.X;
                    rect.Width = e.X - startPoint.X;
                }
                else
                {
                    rect.X = e.X;
                    rect.Width = startPoint.X - e.X;
                }
                if (e.Y > startPoint.Y)
                {
                    rect.Y = startPoint.Y;
                    rect.Height = e.Y - startPoint.Y;
                }
                else
                {
                    rect.Y = e.Y;
                    rect.Height = startPoint.Y - e.Y;
                }


                panelArea.Invalidate();

            }

        }

        private void panelArea_MouseUp(object sender, MouseEventArgs e)
        {

            endPoint.X = e.X;
            endPoint.Y = e.Y;

            drawSPaint = false;

            if (rect.Width > 0 && rect.Height > 0)
            {
                if (IsShapeRectangle == true)
                {
                    listOfShapes.Add(new TheRectangles(rect, currentColor, currentBoarderColor, brushThickness));
                }
                else if (IsShapeCircle == true)
                {
                    listOfShapes.Add(new TheCircles(rect, currentColor, currentBoarderColor, brushThickness));
                }
                else if (IsShapeLine == true)
                {
                    listOfShapes.Add(new TheLines(startPoint, endPoint, currentColor, currentBoarderColor, brushThickness));
                }

                panelArea.Invalidate();
            }
        }


        private void rectangleToolStripMenuItem_Click(object sender, EventArgs e)
        {
            IsShapeRectangle = true;
            IsShapeCircle = false;
            IsShapeLine = false; 
        }

        private void ellipseToolStripMenuItem_Click(object sender, EventArgs e)
        {
            IsShapeRectangle = false;
            IsShapeCircle = true;
            IsShapeLine = false; 
        }

        private void lineToolStripMenuItem_Click(object sender, EventArgs e)
        {
            IsShapeCircle = false;
            IsShapeRectangle = false;
            IsShapeLine = true; 
        }

        private void ThicknessLevel0_Click(object sender, EventArgs e)
        {
            brushThickness = 0; 
        }

        private void ThicknessLevel2_Click(object sender, EventArgs e)
        {
            brushThickness = 2; 
        }

        private void ThicknessLevel4_Click(object sender, EventArgs e)
        {
            brushThickness = 4; 
        }

        private void ThicknessLevel6_Click(object sender, EventArgs e)
        {
            brushThickness = 6; 
        }

        private void ThicknessLevel8_Click(object sender, EventArgs e)
        {
            brushThickness = 8; 
        }

        private void ThicknessLevel10_Click(object sender, EventArgs e)
        {
            brushThickness = 10; 
        }

        private void ThicknessLevel12_Click(object sender, EventArgs e)
        {
            brushThickness = 12; 
        }

        private void ThicknessLevel14_Click(object sender, EventArgs e)
        {
            brushThickness = 14; 
        }

        private void FillColour_Click(object sender, EventArgs e)
        {

            ColorDialog fillColourDialog = new ColorDialog();
            fillColourDialog.ShowDialog();
            currentColor = fillColourDialog.Color;
            panelArea.Invalidate(); 
        }

        private void button1_Click(object sender, EventArgs e)
        {

            ColorDialog fillColourDialog = new ColorDialog();
            fillColourDialog.ShowDialog();
            currentBoarderColor = fillColourDialog.Color;
            panelArea.Invalidate(); 
        }


    }
}

Как остановить мерцание ?

* ОБНОВЛЕНИЕ: * Этот код действительно отлично работает, когда я рисую прямо в форме. Однако, когда я пытаюсь рисовать на панели, мерцание становится проблемой