Control arrays in VB.NET

One of the things that I really liked (and used quite a bit) in the VB6 IDE was the ability to use the design surface to create a form with a bunch of controls with the same name as a control array. You would create the controls on the design page, give it the same name as another control, and the Index property would automatically be incremented. This would then let me use a loop to manipulate and examine these controls.

This functionality is missing in VB.NET, as I discovered when I tried to do my first .NET Compact Framework application way back when Visual Studio 2003 was shiny and new, and has continued to be missing from the feature set in VS2005 and VS2008.

Microsoft is not much help on this front. Their solution is to create the forms in code, as described in this article:

Not so helpful link (link redacted)

But I like using the design surface to create forms. A co-worker suggested we try to do a test in C# and tamper with the designer.cs file to create an array of controls in there, which worked OK. The big problems there were that the controls showed up on the design surface, but they could not be clicked and modified. Also, when we added a control to the form and saved it, all of the customizations we made to the designer file disappeared. (Oops.)

So instead, what I am now doing is creating my forms in the designer as before, with each control of the set having a different name with a number after it (such as cboName0, cboName1, etc.), referring to the index of the control in the array. At the top of the form’s class I have the arrays defined:

Dim cboName(10) as ComboBox
Dim lblNumber(10) as Label

Then, in the form load event, I am calling this subroutine:

Sub SetUpControlArrays()
    For Each cb In Me.Controls.OfType(Of ComboBox)()
        If cb.Name.Contains("cboName") Then
            cboName(CInt(cb.Name.Replace("cboName", ""))) = cb
        End If
    For Each lbl In Me.Controls.OfType(Of Label)()
        If lbl.Name.Contains("lblNumber") Then
            lblNumber(CInt(lbl.Name.Replace("lblNumber", ""))) = lbl
        End If
End Sub

Now I have the ability to address the controls in the same way that I used to do in VB6. The fact that I lived with this missing feature for about 6 years and just now figuring out a decent way around the problem pretty much guarantees that VS2010 will put the control arrays back in.

EDIT: At the request of a Strong Bad fan who shall remain nameless, I changed up the code above to be a bit more friendly. The previous code only extracted the rightmost 1 character from the name of the control on the design surface, which would not work if you had a control name such as cboName10.

One Comment

  1. John Boker says:

    What is this? Did the quadratic formula explode? I see a “Strong ba” in there, but it’s getting eaten… by some… Linux or something. Wait a minute! It’s VB!

Leave a Reply