requires_category
Specifies the required component categories of the target class.
Syntax
[ requires_category(
requires_category) ]
Parameters
requires_category
The ID of the required category.
Remarks
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.
Example
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 {};
Requirements
| 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.