Microsoft VFPCOM Utility

The Microsoft VFPCOM Utility (VFPCOM.dll) is a specialized COM component released by Microsoft during the Visual FoxPro 6.0 era to bridge the gap between Visual FoxPro (VFP) and standard COM (Component Object Model) events.

Before Visual FoxPro 7.0 introduced native language support for event binding (via EVENTHANDLER()), VFP developers could not natively respond to events fired by external COM objects or ActiveX controls. The VFPCOM utility effectively “unlocked” these component features, allowing VFP 6.0 and 5.0 applications to participate in two-way communication with external data sources and components. Core Features Unlocked by VFPCOM

The utility primarily exposes two powerful methods that allow VFP to bind to and interact with outside components: 1. BindEvents() — Two-Way Event Communication

The Problem: In VFP 6.0, your code could call a method on a COM object (like Microsoft Excel or an ADO Recordset), but if that object fired an internal event (e.g., “Data Download Complete” or “Row Changed”), VFP had no native way to “listen” or respond to it.

The Solution: BindEvents() connects an event source (the external COM object) to an event sink (a VFP class custom-written to handle those events).

Example: It allows a VFP application to listen directly to an ADO Recordset and execute custom VFP code the exact moment data changes on the server. 2. ExportEvents() — Automated Interface Setup

The Problem: Writing a custom class in VFP that exactly matches the method signatures and parameters required by an external COM object’s event interface is tedious and error-prone.

The Solution: ExportEvents() reads an external component’s type library and automatically writes the VFP skeleton code for you. It formats the required DEFINE CLASS syntax and maps out all necessary event methods, ensuring 100% compatibility. 3. Native ADO Cursor Conversions

VFPCOM also includes helper methods designed to smoothly convert data between native Visual FoxPro cursors and ADO (ActiveX Data Objects) Recordsets:

RS2Cursor(): Converts an ADO Recordset directly into a native, blazing-fast VFP cursor.

Cursor2RS(): Converts a local VFP cursor into an ADO Recordset so it can be passed over the web or to non-VFP components. Basic Implementation Workflow

To use the utility in legacy VFP code, you instantiate the control, export the interface definitions, and tie them together:

1. Create the VFPCOM object oVFPCOM = CREATEOBJECT(“vfpcom.comutil”) * 2. Export the event structure of an external component to a text file oVFPCOM.ExportEvents(oExternalObject, “C:\MyEvents.prg”) * 3. (After defining your custom event-handler class based on that export) * Bind the external object’s events to your VFP handling object oVFPCOM.BindEvents(oExternalObject, oMyVFPEventHandler) Use code with caution. Legacy Status & Modern Relevance

Replaced in VFP 7.0, 8.0, and 9.0: Microsoft integrated these capabilities directly into the core language starting with Visual FoxPro 7.0. The native EVENTHANDLER() function replaced BindEvents(), and the Object Browser took over type library exporting.

Maintenance Value: While native language features replaced it long ago, understanding the VFPCOM utility is highly critical if you are maintaining or migrating legacy 1990s-era Visual FoxPro 6.0 applications. If you are working on a specific codebase, let me know:

Which version of Visual FoxPro you are targeting (VFP 6, 9, etc.)?

What external component or ActiveX control you are trying to bind to?

Whether you are attempting to modernize or migrate this legacy functionality?

I can provide the exact code syntax or modern equivalents suited to your project.