C# tips : How to draw on a picturebox image using mouse by c#

if u want to draw something on a picture u can use microsoft paint, but if you want do it by ur c# code, i think this article will help you.

i make a win form application to draw by mouse. u can select the pensize as u wish. It is only a tricks between three mouse event on a picture they are

• mouse up
• mouse down
• mouse move

to use the software to u have to insert an image to picture box then chose color and size of brush. then start to draw by mouse press on image. like below image

after inserting u can draw as u like

the coding is fairly easy, u have to check mouse event is pressed or not, the write a rectangle in mouse position. like below



 bool draw = false;
   int s = 3;
  Color color = Color.Red;
 private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            draw = true;
            Graphics g = Graphics.FromImage(mainimage);
            Pen pen1 = new Pen(color, 4);
            g.DrawRectangle(pen1, e.X, e.Y, 2, 2);
            g.Save();
            pictureBox1.Image = mainimage;
        }
        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            draw = false;
        }

        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (draw)
            {
                Graphics g = Graphics.FromImage(mainimage);
                SolidBrush brush = new SolidBrush(color);
                g.FillRectangle(brush, e.X, e.Y, s, s);
                g.Save();
                pictureBox1.Image = mainimage;
            }
        }

u can get full source code from here