'_____________________________________________________________________________________________

'                                           USING CLASSES PART 4:
'                                               SHARED MEMBERS

'This program allows us to add two numbers. It uses a class called DoMath which contains one
'function/method called Add.

'This function is declared as a Shared Member of the class so that we can access it from anywhere
'inside our application. The main purpose in showing you this creepy program is that in the btnGO_click event,
'you will notice that I do not have to first create a new instance of DoMath using the New keyword. I can
'simply use the Add method.

'This is like placing a function inside the form itself or by putting it in a general code module.
'But this is a way of showing you yet another way to interact with  a class you create. 
'By putting functions inside their own module/class, it organizes your stuff and makes it easy to add this
'class to a new project.

'_____________________________________________________________________________________________

Option Explicit On

Public Class frmMain

    Private Sub btnGO_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGO.Click
        '---We can use this method - without instantiating a DoMath object because we created the method (function)
        '   as being shared in the DoMath Class


        Dim First As Integer
        Dim Second As Integer
        Dim Result As Integer

        First = txtFirst.Text
        Second = txtSecond.Text

        Result = DoMath.Add(First, Second)     'just use the add method of DoMath
        txtAnswer.Text = Result
    End Sub
    
    
    
    '--------------------------------------------------------------------------------------------

'                                                          DO MATH CLASS

'This little class contains 1 method called Add which adds 2 numbers that are passed to it.
'This method is declared as Shared so other parts of my app can use it freely without first
'creating a new instance of DoMath first. This is the equivalent of placing a Public or Friend function
'inside a general C# module. Since Functions in a class are public by default, you do not have to
'include Public Shared....you can just use Shared if you like. I put them both here for completeness.
'--------------------------------------------------------------------------------------------



Public Class DoMath
    Public Shared Function Add(ByVal a As Integer, ByVal b As Integer) As Integer

        Return a + b

    End Function
End Class