int width = 0;
int height = 0;
int count = 8;
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
width = ((pictureBox1.Width) / count);
height = ((pictureBox1.Height) / count);
for (int i = 0; i < count; i++)
{
for (int j = 0; j < count; j++)
{
Pen pen = new Pen(Color.Blue, 2);
Rectangle r = new Rectangle(i * width, j * height, width, height);
e.Graphics.DrawRectangle(pen, r);
}
}
}