C#

using System.Drawing;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        
        public Form1()
        {
            InitializeComponent();
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            using (Pen pen = new Pen(Color.Black))
            {
                e.Graphics.DrawLine(pen, Point.Empty, new Point(ClientSize.Width, ClientSize.Height));
            }
            base.OnPaint(e);
        }
    }
}

using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        List<Point> points = new List<Point>();
        public Form1()
        {
            InitializeComponent();
            MouseClick += new MouseEventHandler(Form1_MouseClick);
        }

        void Form1_MouseClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                points.Add(e.Location);
                Invalidate();
            }
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            foreach (Point point in points)
            {
                e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
                e.Graphics.DrawEllipse(Pens.Red, point.X, point.Y, 2, 2);
            }
            base.OnPaint(e);
        }
    }
}

musefan wrote:

Obvisouly I could make two version of the application one for 32Bit that uses the 32Bit DLL and one for 64bit that uses the 64Bit dll, but is this needed?

d@nish wrote:

and as stated by Nagy

dojohansen wrote:

most other forums have solved this problem by using square brackets for a few basic formatting tags