共用方式為


DYNAMIC_DOWNCAST

Provides a handy way to cast a pointer to a pointer to a class object while checking to see if the cast is legal.

DYNAMIC_DOWNCAST(class, pointer )

Parameters

  • class
    The name of a class.

  • pointer
    A pointer to be cast to a pointer to an object of type class.

Remarks

The macro will cast the pointer parameter to a pointer to an object of the class parameter's type.

If the object referenced by the pointer is a "kind of" the identified class, the macro returns the appropriate pointer. If it is not a legal cast, the macro returns NULL.

Requirements

Header: afx.h

See Also

Reference

STATIC_DOWNCAST

dynamic_cast Operator

Concepts

MFC Macros and Globals