Change a CheckBox or OptionButton style at runtime

Visual Basic doesn’t let you change the Style property of a CheckBox or an OptionButton control at runtime. However, you can easily do it by manipulating the control’s style bit, with the SetWindowLong API function. Here’s a routine that does the trick:

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" _    (ByVal hWnd As Long, ByVal nIndex As Long) As LongPrivate Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" _    (ByVal hWnd As Long, ByVal nIndex As Long, ByVal newValue As Long) As LongConst GWL_STYLE = (-16)Const BS_PUSHLIKE = &H1000&Sub SetButtonStyle(Ctrl As Control, ByVal Graphical As Boolean)    If Graphical Then        SetWindowLong Ctrl.hWnd, GWL_STYLE, GetWindowLong(Ctrl.hWnd, _            GWL_STYLE) Or BS_PUSHLIKE    Else        SetWindowLong Ctrl.hWnd, GWL_STYLE, GetWindowLong(Ctrl.hWnd, _            GWL_STYLE) And Not BS_PUSHLIKE    End If    Ctrl.RefreshEnd Sub

Using the routine is straightforward. For example, this code changes the style of all the OptionButton controls in the Option1 array

    Dim c As Control    For Each c In Option1        SetButtonStyle c, True    Next