VB Control Naming by Variable - vb6

Question

Dim LineNo as Integer
LineNo = CStr(channel) 'This can have a value of 1 to 100
If LineNo = 1 then
Text1.Text = "Line one selected"
Elseif LineNo = 2 then
Text2.Text = "Line one selected"
'Etc etc
End if
I need to replace the number "1" in Text1.Text and every other TextBox with the value of LineNo? For example:
Text{LineNo}.Text
So I would not have to do a repeated "If" and have a smaller one line code like this:
Text{LineNo}.Text = "Line " & LineNo & " selected"
How would I do this?

Answer 1

Look into a Control array of text boxes. You could have txtLine(), for example, indexed by the channel number.
LineNo = CStr(channel)
txtLine(channel).Text = "Line " & LineNo & " selected"
To create the array, set the Index property of each of the text boxes to an increasing integer, starting at 0.

Answer 2

If you have a finite and relatively small number, you can use a property. I've used this approach with up to 30+ elements in a pinch. Super simple, easy pattern to recognize and replicate in other places. A bit if a pain if the number of elements changes in the future, but extensible nevertheless.
It uses the Choose statement, which takes an index N and returns the Nth element (1-based), hence, the check makes sure that N is > 0 and <= MAX (which you would configure).
Public Property Get TextBox txt(ByVal N As Long)
Const MAX As Long = 10
If N <= 0 || N > MAX Then Exit Property ' Will return a "Nothing". You could return the bound element if you prefer
set txt = Choose(Text1, Text2, Text3, Text4, Text5, Text6, Text7, Text8, Text9, Text10)
End Property
Then, you can simply reference them with the Property, much like an alias:
txt(1).Text = "Line 1 text"
txt(2).Text = "Line 2 text"
If you have an arbitrary number, then you are likely using a control array already, which is simpler because it can be referenced by Index already, so you can directly reference it.
If neither of these work for you and you have a very large number of controls, you can scan the Controls collection in a similar Property, attempting to match ctrl.Name with the pattern of your choice (e.g., matching the first 4 characters to the string "Text", thus matching Text1, Text2, etc, for an unlimited number). Theoretically, this should be future-proofed, but that's just theoretical, because anything can happen. What it does do for you is to encapsulate the lookup in a way that "pretends" to be a control array. Same syntax, just you control the value.
Public Property Get TextBox txt(ByVal N As Long)
Dim I As Long
For I = 0 To Controls.Count - 1 ' Controls is zero-based
' Perform whatever check you need to. Obviously, if you have a "Label" named
' "Text38", the assignment will throw an error (`TextBox = Label` doesn't work).
If Left(Controls(I).Name, 4) = "Text" Then
set txt = Controls(I)
End If
Next
' If you want the Property to never return null, you could uncomment the following line (preventing dereference errors if you insist on the `.Text` for setting/getting the value):
' If txt Is Nothing Then Set txt = Text1
End Property
Use the same way as above: txt(n).Text = "..."