2005-11-25-get-subform-control-name.md

GetSubFormControlName.vb

Public Enum ControlNameFormat
   cnfcShortPropertyName
   cnfcLongHierarchicalName
End Enum

Public Function GetSubFormControlName( _
   ByRef frm As Form, _
   Optional ByVal NameFormat As ControlNameFormat = _
      cnfcShortPropertyName) As String

' Tells a subform the name of the control that
' it has been opened in on the main form. Used
' to modify the base subform's source or to
' retrieve special values from its Tag property.
' The NameFormat tells us whether to just provide
' the ctl.Name property or the fully qualified
' form controls collection item name.

' Example:
' Form "MainForm" holding "1stSubForm" in control "fsub1"
' holding "2ndSubForm" in control "fsub2"...
' GSFCN(1stSubForm,Long) = "[Forms]![MainForm]![fsub1]"
' GSFCN(2ndSubForm,Long) = "[Forms]![MainForm]![fsub1].Form![fsub2]"
' GSFCN(2ndSubForm,Short) = "fsub2"

' Developed by Warren Bain on 26/09/2005
' Copyright (c) Thought Croft Pty Ltd.

   Dim ctl As Control
   Dim strResult As String

   On Error Resume Next

   ' Loop through all controls on the parent and test for the
   ' handle of the window of the subsidiary form. If it
   ' matches ours, then we have found the control it opened in
   If Not IsSubForm(frm) Then
      ' We are at the top of the tree, so return name
      If NameFormat = cnfcShortPropertyName Then
         strResult = frm.Name
      ElseIf NameFormat = cnfcLongHierarchicalName Then
         strResult = "[Forms]![" & frm.Name & "]"
      End If
   Else
      For Each ctl In frm.Parent.Controls
         If ctl.ControlType = acSubform Then
            If ctl.Form.hWnd = frm.hWnd Then
               ' Found the right one
               If NameFormat = cnfcShortPropertyName Then
                  ' Just return the name of the control
                  strResult = ctl.Name
               ElseIf NameFormat = cnfcLongHierarchicalName Then
                  ' Add parent plus fully qualified control
                  strResult = GetSubFormControlName(frm.Parent, NameFormat) & ".Form![" & ctl.Name & "]"
               End If
               Exit For
            End If
         End If
      Next ctl
   End If
   GetSubFormControlName = strResult
End Function

Private Function IsSubForm(frm As Form) As Boolean
   ' Is the form currently loaded as a subform?
   Dim strFormName As String
   On Error Resume Next
   strFormName = frm.Parent.Name
   IsSubForm = (Err.Number = 0)
   Err.Clear
End Function