# Chapter 24. Defining Class Methods and Events

Lesson 23 explains how to create a class and give it properties. In this lesson you learn how to add the remaining two key pieces of a class: methods and events.

# METHODS

A method is simply a subroutine or function in the class that other parts of the program can execute. The following code shows how the `Turtle` drawing class described in Lesson 23 might implement its `Move` method:

```' Make the Turtle move the indicated distance in its current direction.
Public Sub Move(ByVal distance As Integer)
' Calculate the new position.
Dim radians As Double = Direction * Math.PI / 180
Dim newX As Integer = CInt(X + Math.Cos(radians) * distance)
Dim newY As Integer = CInt(Y + Math.Sin(radians) * distance)

' Draw to the new position.
Using gr As Graphics = Graphics.FromImage(Canvas)
gr.DrawLine(Pens.Blue, X, Y, newX, newY)
End Using

' Save the new position.
X = newX
Y = newY
End Sub```

### Note

You can download the Turtle example program from the book's web site (at `www.wrox.com` or `www.vb-helper.com/24hourvb.html`) as part of the Lesson24 folder and follow along in its code as you read through this lesson.

The method takes as a parameter the distance it should move. It uses the `Turtle`'s current position and direction to figure out where this move will terminate. It uses some graphics code to draw a line from the current position to the new one (don't worry about the details) and finishes by saving the new position.

That's all there is to adding a method to a class. ...

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