| description | Learn more about: requires_category | |
|---|---|---|
| title | requires_category (C++ COM Attribute) | |
| ms.date | 10/02/2018 | |
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| ms.assetid | a645fdc6-1ef5-414d-8c56-5fe2686d4687 |
Specifies the required component categories of the target class.
[ requires_category(
requires_category) ]requires_category
The ID of the required category.
The requires_category C++ attribute specifies the component categories required by the target class. For more information, see REQUIRED_CATEGORY.
This attribute requires that the coclass, progid, or vi_progid attribute (or another attribute that implies one of these) also be applied to the same element.
The following code requires that the object implement the Control category.
// cpp_attr_ref_requires_category.cpp
// compile with: /LD
#define _ATL_ATTRIBUTES
#include "atlbase.h"
#include "atlcom.h"
[module (name="MyLibrary")];
[ coclass, requires_category("CATID_Control"),
uuid("1e1a2436-f3ea-4ff3-80bf-5409370e8144")]
class CMyClass {};| Attribute context | Value |
|---|---|
| Applies to | class, struct |
| Repeatable | No |
| Required attributes | One or more of the following: coclass, progid, or vi_progid. |
| Invalid attributes | None |
For more information about the attribute contexts, see Attribute Contexts.