Can't remove a user defined field with DI API.

Question

Hi,
I'm using the code below to remove a user field.  However, the first time I run it, I get the message that:
"Ref count for this object is higher then 0"
The second time I run it, I get the message that:
"No matching records found (ODBC -2028)"
As you can see, I am killing the UserFieldsMD object.  In fact, when the function is entered, the object is nothing but later instantiated with oCompany.
The result in both cases is that the field doesn't get removed.  What am I missing?  Any ideas?
Thanks,
Mike
    Public Function RemoveUserField(ByVal FieldName As String, ByVal TableName As String, ByRef ErrMsg As String) As Boolean
        Dim Result As Boolean = False
        Dim Err As Integer
        Dim oUserFieldsMD As SAPbobsCOM.UserFieldsMD
        Try
            If Not FieldExists(TableName, FieldName) Then
                Result = True
            Else
                oUserFieldsMD = oCompany.GetBusinessObject(SAPbobsCOM.BoObjectTypes.oUserFields)
                With oUserFieldsMD
                    .TableName = TableName
                    .Name = FieldName
                    Err = .Remove
                    If Err Then
                        oUtilCompany.GetLastError(Err, ErrMsg)
                        If ErrMsg = "No matching records found (ODBC -2028)" Then
                            Result = True
                        Else
                            ErrMsg = "Was not able to remove field " & FieldName & " from table " & TableName & " programmatically." & vbCrLf & _
                                     "Please remove it manually using the Tools menu."
                        End If
                    Else
                        Result = True
                    End If
                End With
            End If
        Catch ex As Exception
            Throw ex
        Finally
            KillObject(oUserFieldsMD)
        End Try
        Return Result
    End Function
    Public Sub KillObject(ByRef Obj As Object)
        If Not Obj Is Nothing Then ObjectRelease(Obj)
    End Sub
    Private Sub ObjectRelease(ByRef Obj As Object)
        'This routine releases objects that were acquired with oCompany.GetBusinessObject().
        System.Runtime.InteropServices.Marshal.ReleaseComObject(Obj)
        Obj = Nothing
        GC.Collect()
    End Sub

Answer 1

Hi Mike,
The issue with your code is that you are not calling the GetByKey method of the field object. Until you do this the FieldID property is 0 so when the Remove method is called it will not try and remove the correct UDF (if you run SQL profiler then you'll see that SBO is looking for the UDF based on the table and fieldID values).
Something like the following works for me:
private void DeleteUDF(string sTableID, string sFieldName)
    SAPbobsCOM.UserFieldsMD sboField = (SAPbobsCOM.UserFieldsMD)_sboCompany.GetBusinessObject(BoObjectTypes.oUserFields);
    try
        int iFieldID = GetFieldID(sTableID, sFieldName);
        if(sboField.GetByKey(sTableID, iFieldID))
            if (sboField.Remove() != 0)_sboApp.SetStatusBarMessage("Error removing UDF: " + _sboCompany.GetLastErrorDescription(), SAPbouiCOM.BoMessageTime.bmt_Short, true);
    finally
        System.Runtime.InteropServices.Marshal.ReleaseComObject(sboField);
        sboField = null;
        GC.Collect();
private int GetFieldID(string sTableID, string sAliasID)
    int iRetVal = 0;
    SAPbobsCOM.Recordset sboRec = (SAPbobsCOM.Recordset)_sboCompany.GetBusinessObject(BoObjectTypes.BoRecordset);
    try
        sboRec.DoQuery("select FieldID from CUFD where TableID = '" + sTableID + "' and AliasID = '" + sAliasID + "'");
        if (!sboRec.EoF) iRetVal = Convert.ToInt32(sboRec.Fields.Item("FieldID").Value.ToString());
    finally
        System.Runtime.InteropServices.Marshal.ReleaseComObject(sboRec);
        sboRec = null;
        GC.Collect();
    return iRetVal;
Note that the parameter sAliasID is the field name without the U_ prefix.
Kind Regards,
Owen