# ICatInformation

The ICatInformation 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 CoCreateInstance, 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 in Vtable Order

IUnknown Methods | Description
QueryInterface | Returns pointers to supported interfaces.
AddRef | Increments reference count.
Release | Decrements reference count.

ICatInformation Methods | Description
EnumCategories | Returns an enumerator for the component categories registered on the system.
GetCategoryDesc | Retrieves the localized description string for a specific category ID.
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.

See Also

ICatRegister