If Visual FoxPro does not include the features you require for your application, you can extend the capabilities of Visual FoxPro by creating external libraries, for example, a Microsoft ActiveX control (.ocx) file or Visual FoxPro dynamic-link library (FLL) file.

Visual FoxPro includes the Library Construction Kit, which contains the files Pro_Ext.h, WinAPIMS.lib, and OcxAPI.lib so you can create ActiveX controls and FLLs.

Note:
The Library Construction Kit has a limit of 65,000 elements for arrays.

In This Section

Library or ActiveX Object Creation: Explains extending the capabilities of Visual FoxPro by creating external libraries that accomplish tasks required by your application.

How to: Create a Basic ActiveX Object: Describes how to create an ActiveX control.

Creating Visual FoxPro Dynamic-Link Libraries: Provides information about creating Visual FoxPro dynamic-link libraries.

FoxInfo Structure: Describes the FoxInfo structure used to communicate function names and parameter descriptions between Visual FoxPro and your FLL library.

FoxTable Structure: Describes the FoxTable structure which keeps track of all the FoxInfo structures you have for a given library.

How to: Add Visual FoxPro API Calls: Describes how to integrate your external library with Visual FoxPro using Visual FoxPro API routines.

Parameters in External Libraries: Describes how to pass arguments to parameters in external libraries.

How to: Return Values from ActiveX Controls and FLL Libraries: Describes how to return values from external libraries to Visual FoxPro.

Passing Parameters to Visual FoxPro API Functions: Explains how Visual FoxPro API routines require parameters of a particular Visual FoxPro data structure.

Access to Visual FoxPro Variables and Fields: Explains accessing Visual FoxPro variables or field values in your ActiveX control or FLL function.

Memory Management Using the Visual FoxPro API: Provides an overview about managing memory using the Visual FoxPro API.

How to: Manage Memory: Describes how the Visual FoxPro API provides direct access to the Visual FoxPro dynamic memory manager.

How to: Build and Debug Libraries and ActiveX Controls: Describes how to build and debug ActiveX controls and FLLs.

Related Sections

Accessing APIs: Discusses how you can extend an application by taking advantage of external libraries such as Microsoft ActiveX controls or Visual FoxPro dynamic-link libraries (FLLs).

Extending Visual FoxPro with External Libraries: Explains that you can add Microsoft ActiveX controls (.ocx files) to your application, which provides you with new objects to use in forms, to subclass, and to manage the way you work with native Visual FoxPro controls. In addition, you can link to an external library, such as a Visual FoxPro dynamic-link library (FLL) and call the library's functions to use in your own programs.

API Library Construction: Provides reference material about API Library routines, system events, and key codes.