private void CreatePointsAndSizes(PaintEventArgs e)
{

    // Create the starting point.
    Point startPoint = new Point(subtractButton.Size);

    // Use the addition operator to get the end point.
    Point endPoint = startPoint + new Size(140, 150);

    // Draw a line between the points.
    e.Graphics.DrawLine(SystemPens.Highlight, startPoint, endPoint);

    // Convert the starting point to a size and compare it to the
    // subtractButton size.  
    Size buttonSize = (Size)startPoint;
    if (buttonSize == subtractButton.Size)

        // If the sizes are equal, tell the user.
    {
        e.Graphics.DrawString("The sizes are equal.", 
            new Font(this.Font, FontStyle.Italic), 
            Brushes.Indigo, 10.0F, 65.0F);
    }
}

//引入命名空间
using System;
using System.Drawing;

class MainClass
{
  public static int Main(string[] args)
  {
    
    Point pt = new Point(100, 72);
    Console.WriteLine(pt);
    pt.Offset(20, 20);
    Console.WriteLine(pt);
  
    return 0;
  }
}