Microsoft KB Archive/137555

= OLE Controls and Control Containers Guidelines =

Article ID: 137555

Article Last Modified on 3/14/2005

-

APPLIES TO


 * Microsoft Visual FoxPro 3.0 Standard Edition
 * Microsoft Visual FoxPro 5.0 Standard Edition
 * Microsoft Visual FoxPro 6.0 Professional Edition

-



This article was previously published under Q137555



SUMMARY
Ole-cont.exe is a file that contains a document in Microsoft Word version 6.0 for Windows format that provides guidelines for implementing OLE controls and containers that will inter-operate well with other controls and containers.



MORE INFORMATION
The following files are available for download from the Microsoft Download Center:

OLE-Cont.exe

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to Obtain Microsoft Support Files from Online Services

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. Following is an overview from the document:

The purpose of this document is to provide guidelines for implementing OLE controls and containers that will interoperate well with other controls and containers. This document defines the minimum set of interfaces, methods, and features that are required of OLE Controls and Containers to accomplish seamless and useful interoperability.

These guidelines define the minimum set of functionality that is required of a control and container; it therefore also describes the minimum set of functionality that a control can expect of a container and vice versa. This enables controls and container developers to assume a standard set of functionality and to reasonably rely on the existence of that functionality. Of course, OLE standard return-checking conventions should always be followed.

There are many optional features that OLE controls and OLE control containers can choose to implement, which may or may not be essential to correct operation of the control or container. Some optional features are grouped into function groups. A control or a control container can choose to implement any of these function groups; function groups are not cumulative, so a control or container can support one group without necessarily supporting another. It is important for a control or container to degrade gracefully if a feature or function group it uses is not available. If an optional feature that is essential for correct operation is not available, then the control or container should alert the user and/or should not instantiate itself.

It is important for controls and containers that require optional features (or features specific to a certain container) to be marketed and packaged as such. For example, a control that requires Visual Basic's data-bound list box should be marketed as a Visual Basic-specific control because it cannot run in other containers.

These guidelines explicitly define those features, interfaces, methods, and properties that are mandatory for OLE controls and control containers. Any feature, interface, method, property, or function group that is not explicitly stated as mandatory in these guidelines should be considered optional.

Additional query words: OLE-Cont

Keywords: kbinfo kbdownload kbinterop kbfile kbautomation KB137555

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.