مبتدی: رسم سلول در یک مستطیل با استفاده از GDI+

private void Form1_Paint(object sender, PaintEventArgs e)
{
Pen redpen = new Pen(Color.Red, 3);
Pen greenpen = new Pen(Color.Green, 3);
int numOfCells = 50;
int cellSize = 30;
Graphics g = this.CreateGraphics();
for (int i = 0; i < numOfCells; i++)
{
// Vertical
g.DrawLine(redpen, i * cellSize, 0, i * cellSize, numOfCells * cellSize);
// Horizontal
g.DrawLine(greenpen, 0, i * cellSize, numOfCells * cellSize, i * cellSize);
}
redpen.Dispose();
greenpen.Dispose();
}