INFO: What Is an OCA file? (149429)
The information in this article applies to:
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows 4.0
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows 4.0
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows 4.0
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
- Microsoft Visual Basic Control Creation Edition for Windows 5.0
- Microsoft Visual Basic Learning Edition for Windows 5.0
- Microsoft Visual Basic Professional Edition for Windows 5.0
- Microsoft Visual Basic Enterprise Edition for Windows 5.0
This article was previously published under Q149429 SUMMARY
For every custom control file (.OCX) that Visual Basic uses, there is an
accompanying .OCA file of the same file name. For example, GRAPH16.OCX has
an accompanying .OCA file called GRAPH16.OCA. An .OCA file is a binary file
that functions as both an extended type library file and a cache for the
custom control file.
MORE INFORMATION
A type library is a file or component within another file that contains OLE
Automation standard descriptions of exposed objects, properties, and
methods. The actual working type library for a custom control used in
Visual Basic is a combination of the type library of the control itself and
the additional properties provided by the framework that wrap the control.
Some of the properties of the control are provided by the framework and
some by the control itself. Programmatically, the properties from the
framework and the control all appear as properties of the control.
In order for these properties to appear, Visual Basic creates an extended
type library when the control is loaded into the toolbox. Because the
process of reading the control's type library and creating the extended
type library is time consuming, Visual Basic caches the extended type
library information into an OCA file.
If you delete the OCA file for a control Visual Basic recognized, Visual
Basic will recreate the .OCA file when you load a project requiring the
control. This recreation process comes with a time penalty.
| Modification Type: | Minor | Last Reviewed: | 7/14/2004 |
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| Keywords: | kbinfo KB149429 |
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