При нажатии на кнопку не происходит рисование

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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            this.DoubleBuffered = true;
            this.Paint += new PaintEventHandler(Form1_Paint);  
        }
        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            e.Graphics.DrawRectangle(Pens.Black, new Rectangle(10, 10, 50, 70)); //прямоугольник
            e.Graphics.DrawLine(Pens.Red, new Point(10, 10), new Point(60, 80)); //линия
            e.Graphics.FillRectangle(Brushes.Black, 70, 10, 50, 70); //чёрный прямоугольник
            e.Graphics.DrawArc(Pens.Blue, new Rectangle(130, 10, 70, 70), 0, 360);//круг
            e.Graphics.FillPie(Brushes.Green, new Rectangle(210, 10, 70, 70), 0, 360);//закрашенный циркуль
            e.Graphics.DrawEllipse(Pens.Blue, new Rectangle(290, 10, 40, 70));//овал
        }
    }
}

private void button1_Click(object sender, EventArgs e)
{
    this.DoubleBuffered = true;
    this.Paint += new PaintEventHandler(Form1_Paint);
    this.Invalidate();
}

private void Form1_Load(object sender, EventArgs e)
{
    this.DoubleBuffered = true;
    this.Paint += new PaintEventHandler(Form1_Paint);
}
 
private void button1_Click(object sender, EventArgs e)
{
    this.Invalidate(); //вызываем перерисовку
}
 
private void Form1_Paint(object sender, PaintEventArgs e)
{
    //рисуем
}

bool needPaint = false; //рисовать/не рисовать
private void Form1_Load(object sender, EventArgs e)
{
    this.DoubleBuffered = true;
    this.Paint += new PaintEventHandler(Form1_Paint);
}
 
private void button1_Click(object sender, EventArgs e)
{
    this.Invalidate();
    needPaint = !needPaint;
}
 
private void Form1_Paint(object sender, PaintEventArgs e)
{
    if (needPaint)
    {
        //рисуем
    }
}