Why Property Pages Might Be Missing on OLE Controls

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

SUMMARY

This article describes what property pages are and suggests diagnostics for situations where a property page for a particular OLE control (.OCX file) might not appear.

MORE INFORMATION

Property pages are the interface through which a control's properties may be viewed and/or edited at design time. Each related set of properties appears in its own property page. To see them, right-click the OCX at design time, and choose Properties from the Context menu.

There are two kinds of property pages, Custom and Stock. Custom property pages are those that need to be defined by you, the developer. Stock property pages (like Colors, Pictures, and Fonts) are already supplied by the control development kit (CDK).

Property pages are objects too. Each type of property page defines a new OLE class and has a CLSID (class identifier) assigned to it. Thus, property pages for OLE controls rely on the system registry. If a system registry entry for a property page is missing for some reason, that property page is no longer accessible. While this will not cause any errors, the property page will always be invisible.

For custom property pages, this problem can be fixed by re-registering the OCX. This can be done by choosing Custom Controls from the Tools menu, browsing to find the control, and then selecting the appropriate .OCX file.

Standard property pages are provided by OC30.DLL for the 32-bit Visual Basic and OC25.DLL for 16-bit Visual Basic. If the registry entries for these DLLs are missing, then these property pages will be missing for all controls that use them. To re-register these DLLs, reinstall Visual Basic version 4.0.