Q137555: OLE Controls and Control Containers Guidelines

Article: Q137555
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,5.0,6.0
Operating System(s): 
Keyword(s): kbfile kbinterop kbAutomation kbvfp300 kbvfp500 kbvfp600 kbDSupport
Last Modified: 11-NOV-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 6.0 
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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
  (http://download.microsoft.com/download/fox30pro/info/1/WIN98/EN-US/OLE-Cont.exe)

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

  Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of
posting to scan this file for viruses. Once posted, the file is housed on secure
servers that 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

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Keywords          : kbfile kbinterop kbAutomation kbvfp300 kbvfp500 kbvfp600 kbDSupport 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP500 kbVFP600
Version           : WINDOWS:3.0,5.0,6.0
Issue type        : kbinfo

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