How to Determine Selected Control from Array of Option Buttons

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SUMMARY

A common programming task in Visual Basic, given a control array of option buttons, is to determine which option button in the array is selected. The option button that is selected will have its Value property set to True, while all others will have Value properties of False. This article outlines a short function that will return the index of the selected option button when it is passed a reference to a control array of option buttons. It will work correctly even some indexes are skipped or not present in the control array. In addition, to avoid logic errors in writing code, it will fail and return a -1 if it is passed a control array of another type of object (like a check box). The function was written by Bruce McKinney, author of Hardcore Visual Basic, which is published by Microsoft Press.

MORE INFORMATION

The code for the function is:

Function GetOption(opts As Object) As Integer

    On Error GoTo GetOptionFail
    Dim opt As OptionButton
    For Each opt In opts
        If opt.Value Then
            GetOption = opt.Index
            Exit Function
        End If
    Next

    GetOption = -1

This function can be called like this:

myVariable = GetOption(optMyButtons)   'Control syntax OK