using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
public class MainForm : Form {
private List myPts = new List();
public MainForm() {
this.Text = "Basic Paint Form";
this.Paint += new PaintEventHandler(MainForm_Paint);
this.MouseDown += new MouseEventHandler(MainForm_MouseDown);
}
void MainForm_MouseDown(object sender, MouseEventArgs e) {
myPts.Add(new Point(e.X, e.Y));
Invalidate();
}
public void OnPaint(PaintEventArgs e) {
Graphics g = e.Graphics;
g.DrawString("Hello GDI+", new Font("Times New Roman", 20),Brushes.Green, 0, 0);
foreach (Point p in myPts)
g.FillEllipse(Brushes.Firebrick, p.X, p.Y, 10, 10);
}
}