ACC: CreateControl Creates Empty Container for OLE Controls

ID: Q147134

The information in this article applies to:

• Microsoft Access versions 7.0, 97

SYMPTOMS

Advanced: Requires expert coding, interoperability, and multiuser skills.

When you use the CreateControl() function to programmatically create an OLE control, only an empty container is created.

CAUSE

The CreateControl() function does not add the OLE data needed to make the control functional. This occurs even if the procedure sets the Class or OLEClass properties of the control.

RESOLUTION

In order to create an OLE control at run time, you must first create a "template" form which contains all OLE controls that your procedure needs to create at run time. Then, the procedure must set the OLEData property of the new custom control to the OLEData property of the OLE control on the "template" form.

Create a form with all OLE controls that you plan for your procedure to create at run time. The procedure must set the OLEData property of the new OLE control to the OLEData property of the appropriate control on the template form. The following steps demonstrate how to do this with the Calendar control included with Microsoft Access.

This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to your version of the "Building Applications with Microsoft Access" manual.

1. Open the sample database Northwind.mdb.

2. Create a new blank form named Template.

3. Insert a Calendar control and name it Calendar.

4. Create a module and type the following line in the Declarations section

   if it is not already there:

      Option Explicit

      Sub CreateCalendar()
         Dim frm As Form
         Dim ctl As Control
         DoCmd.OpenForm "Template", acDesign , , , , acHidden
         Set frm = CreateForm()
         Set ctl = CreateControl(frm.Name, acCustomControl, acDetail)
         ctl.OLEData = Forms!Template!Calendar.OLEData
         DoCmd.Restore
         DoCmd.Close acForm, "Template"
      End Sub

   and then press ENTER:

      CreateCalendar

   Note that a new form is created with a Calendar control.

MORE INFORMATION

Steps to Reproduce Behavior

1. Open the sample database Northwind.mdb.

2. Create a module and type the following line in the Declarations section

   if it is not already there:

      Option Explicit

      Sub CreateCalendar()
         Dim frm As Form
         Dim ctl As Control
         Set frm = CreateForm()
         Set ctl = CreateControl(frm.Name, acCustomControl, acDetail)
         ctl.Class = "MSACAL.MSACALCtrl.7"
         ctl.OLEClass = "Calendar Control"
      End Sub

   and then press ENTER:

       CreateCalendar

   Note that a new form is created with an empty OLE control container
   even though the procedure set the Class and OLEClass properties.

REFERENCES

For more information about the CreateControl() function, search the Help Index for "CreateControl Function," or ask the Microsoft Access 97 Office Assistant.

Additional query words:

Keywords          : kbprg
Version           : 7.0 97
Platform          : WINDOWS
Hardware          : x86
Issue type        : kbprb

Last Reviewed: November 20, 1998