Example of Class

Circle.cs

Public Class Circle

    Private cradius As Double

    Public Property Radius() As Double

        Get

            radius = cradius

        End Get

        Set(ByVal value As Double)

            If value < 0 Then

                msgbox("Wrong Input:")

            Else

                cradius = value

            End If

        End Set

    End Property

 

    Public Function Area() As Double

        Return math.pi * radius ^ 2

    End Function

 

    Public Function Circumfrence() As Double

        Return 2 * math.pi * radius

    End Function

End Class

Public Class Form4

 

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim c As New circle

        c.Radius = Val(TextBox1.Text)

        MsgBox("Area = " & c.Area)

        MsgBox("Circumfrence =" & c.Circumfrence)

    End Sub

 

End Class