How do I call a method from the base class

[Audie7734]

REF: http://msdn.microsoft. com/en-us/library/aa289500(v=vs.7 1).aspx (I added a RichTextBox to Form1)

The above reference is where I got the code below.
This code adds buttons to Form1. When a button is clicked a messagebox appears stating what button was clicked. I want to have the ClickHandler fill a RichTextBox on Form1 (I added a RTB to Form1). My problem is I can't do a Dim xForm As New Form1 to fill the RTB from the ButtonArray Class. I can place my file's text in a MessageBox so I know the code I added is correct. I also tried placing a Property method on Form1 and using a Accessor to fill the RTB, however it also requires Dim xForm As New Form1. How can I get my data from files to the RichTextBox on Form1 from the ClickHandler in the ButtonArray Class? See ButtonArray Class Below.

Imports System.IO
Imports System.Text
Imports System.Collecti ons.CollectionB ase

Public Class ButtonArray
Inherits System.Collecti ons.CollectionB ase

Dim objReader As StreamReader
Dim strRead As String

Private ReadOnly HostForm As System.Windows. Forms.Form

Public Function AddNewButton() As System.Windows. Forms.Button
'Create a new instance of the Button class.
Dim aButton As New System.Windows. Forms.Button
'Add the button to the collection's internal list.
Me.List.Add(aBu tton)
'Add the button to the controls collection of the form
'referenced by the HostForm field.
HostForm.Contro ls.Add(aButton)
'Set initial properties for the button object.
aButton.Height = 30 'I added this.
aButton.Width = 40 'I added this.
aButton.Top = Count * 30 '25 I changed this to 30 from 25.
aButton.Left = 50
aButton.Tag = Me.Count
aButton.Text = "Button" & Me.Count.ToStri ng()
AddHandler aButton.Click, AddressOf ClickHandler
Return aButton
End Function

Public Sub New(ByVal host As System.Windows. Forms.Form)
HostForm = host
Me.AddNewButton ()
End Sub

Default Public ReadOnly Property Item(ByVal Index As Integer) As System.Windows. Forms.Button
Get
Return CType(Me.List.I tem(Index), System.Windows. Forms.Button)
End Get
End Property

Public Sub Remove()
'Check to be sure there is a button to remove.
If Me.Count > 0 Then
'Remove the last button added to the array from the host form
'controls collection. Note the use of the default property in
'accessing the array.
HostForm.Contro ls.Remove(Me(Me .Count - 1))
Me.List.RemoveA t(Me.Count - 1)
End If
End Sub

Public Sub ClickHandler(By Val sender As Object, ByVal e As System.EventArg s)
Dim key As String
Dim keyBuilder As New StringBuilder

'MessageBox.Sho w("You have clicked Button " & CType(CType(sen der, System.Windows. Forms.Button).T ag, String))

'MessageBox.Sho w("You have clicked Button " & CType(CType(sen der, System.Windows. Forms.Button).T ext, String))

'I added this section. I want text read from file to be placed in the
'RichTextBox (rtbKeys) on Form1. Dim xForm As New Form1 doesn't work.
key = CType(CType(sen der, System.Windows. Forms.Button).T ext, String)
key = key.Substring(5 , key.Length - 5)

If File.Exists("C: \Securitas\Keys \" & key & "\" & key & ".txt") Then
objReader = File.OpenText(" C:\Securitas\Ke ys\" & key & "\" & key & ".txt")
Do Until objReader.Peek = -1
strRead = objReader.ReadL ine
If strRead <> Nothing Then
keyBuilder.Appe nd(strRead)
keyBuilder.Appe nd(vbCrLf)
End If
Loop
objReader.Close ()
End If
MsgBox(keyBuild er.ToString().T rimEnd) 'This works.
End Sub
End Class

[Oralloy]

I'm working with VBA in access, so this is just a guess:

Dim xForm As Form1 
Set xForm = new Form1

Merry New Year!
Oralloy

[Joseph Martell]

Remember that a form is just a class like any other class in VB/C#. The only difference between a form, like Form1 in your case, and a string is that the Visual Studio IDE treats the form class in a very special way. It gives you a visual form editor. When you write:

Dim xForm as New Form1()

you are creating a new instance of Form1. Remember that when you created an instance of your ButtonArray class, you passed a reference to your, already running, instance of Form1. Your ButtonArray is holding a reference to Form1 in the HostForm variable.

However, HostForm is of type Form, which means that whatever extra methods or properties you added to Form1 are inaccessible through HostForm because the reference has been up-cast to a more general type. So close, yet so far away.

One solution is to change the type of HostForm to Form1 and to change the type of the parameter passed in the ButtonArray constructor to Form1 as well. This will preserve the type of the reference (no up-casting) and allow you to access the rich text box and any methods that you have added to your Form1 class.

I would be remiss if I didn't point out that the downside of this course of action is that you are "tightly coupling" your button array to your particular Form1 class. This means that your ButtonArray class can only be used with your particular form or its descendants. If the ButtonArray class is meant to be a distributable class that multiple people will use in different contexts, then you have a problem. If you are just using this as an exercise to teach yourself something, then there really is no problem with tightly coupling your class to your form.

I know that this is a pretty complicated explanation, but just remember that "New" keyword creates a new object every time you use it. If you want a reference to an existing object, then you will not get it by using the "New" keyword.

[Audie7734]

I tried the SET keyword, it caused a syntax error.

[Joseph Martell]

The SET keyword is deprecated in modern VB. In VBA it is still used, but that is because VBA is based on VB6. VB6 handles objects in a very strange, and rather clunky way.

[Audie7734]

I tried changing the HostForm to Form1. It still didn't work. The problem arises when I tried to make a new instance of Form1. However I tried something that works but I don't think it is very productive. I made a global varible in the ButtonArray Class and a Property Method to access the varible.

Dim xKey As String

Public Property AddKeys()
Get
Return xKey
End Get
Set(ByVal Value)

End Set
End Property

Then I used the Timer Function to update the Text in my RichTextBox.

Private Sub Timer1_Tick(ByV al sender As System.Object, ByVal e As System.EventArg s) Handles Timer1.Tick
rtbKeys.Text = MyControlArray. AddKeys()
End Sub

Is there a way to do this by:
(1) reacting to the clickEvent in the ButtonArray Class? although I don't think this works between classes.
(2) reacting to a change of a varible in another class.