How to draw on a Windows Form using C# .NET

1. Create a new Windows Forms Application on Visual Studio

2. In the design mode click on the form

3. On the properties window click on events

4. Double click the "Paint" event

and the final step:

5. Put the code below in the file that opens:

using System;

using System.Drawing;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        private Bitmap DrawingArea;  // Area to draw on.

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            DrawingArea = new Bitmap(

                    this.ClientRectangle.Width,

                    this.ClientRectangle.Height,

                    System.Drawing.Imaging.PixelFormat.Format32bppArgb);

            using (var canvas = Graphics.FromImage(DrawingArea))

            {

                canvas.Clear(Color.Transparent);

                canvas.FillPolygon(Brushes.Black, new PointF[] { new PointF(10, 10), new PointF(0, 0), new PointF(0, 10) });

            }

            this.Invalidate();

        }

        private void Form1_Paint(object sender, PaintEventArgs e)

        {

            e.Graphics.DrawImage(DrawingArea, 0, 0, DrawingArea.Width, DrawingArea.Height);

        }

    }

}