ICatInformation:IUnknown
This interface provides methods for obtaining information about the categories implemented or required by a certain class, as well as information about the categories registered on a given machine.
When to Implement
There is no need to implement this interface. The Component Category Manager, a system-provided COM object that can be instantiated by using the CoCreateInstance function, implements ICatInformation.
When to Use
Call the methods of ICatInformation to obtain a listing of available categories, enumerate classes that belong to a particular category, and determine if a class belongs to a specific category.
Information on using component categories can be found in Component Categories Manager Implementation.
Methods
The following table shows the methods for this interface in the order that the compiler calls the methods. Like all COM interfaces, this interface inherits the methods for the IUnknown interface.
| IUnknown method | Description |
|---|---|
| QueryInterface | Returns pointers to supported interfaces. |
| AddRef | Increments reference count. |
| Release | Decrements reference count. |
| ICatInformation method | Description |
|---|---|
| EnumCategories | Returns an enumerator for the component categories registered on the system. |
| GetCategoryDesc | Retrieves the localized description string for a specific category identifier. |
| EnumClassesOfCategories | Returns an enumerator over the classes that implement/require a certain set of categories. |
| IsClassOfCategories | Determines if a class implements/requires the specified categories. |
| EnumImplCategoriesOfClass | Returns an enumerator over the CATIDs implemented by the specified class. |
| EnumReqCategoriesOfClass | Returns an enumerator over the CATIDs required by the specified class. |
Remarks
To determine whether the platform supports this interface, see Determining Supported COM APIs.
Requirements
OS Versions: Windows CE 3.0 and later.
Header: Comcat.h, Comcat.idl.
Link Library: Ole32.lib, Uuid.lib.
See Also
Last updated on Wednesday, April 13, 2005
© 2005 Microsoft Corporation. All rights reserved.