ENUMRESTYPEPROCA callback function (libloaderapi.h)

An application-defined callback function used with the EnumResourceTypes and EnumResourceTypesEx functions. It receives resource types. The ENUMRESTYPEPROC type defines a pointer to this callback function. EnumResTypeProc is a placeholder for the application-defined function name.


ENUMRESTYPEPROCA Enumrestypeproca;

BOOL Enumrestypeproca(
  [in, optional] HMODULE hModule,
                 LPSTR lpType,
  [in]           LONG_PTR lParam


[in, optional] hModule


A handle to the module whose executable file contains the resources for which the types are to be enumerated. If this parameter is NULL, the function enumerates the resource types in the module used to create the current process.



The type of resource for which the type is being enumerated.

Alternately, rather than a pointer, this parameter can be MAKEINTRESOURCE(ID), where ID is the integer identifier of the given resource type. For standard resource types, see Resource Types. For more information, see the Remarks section below.

[in] lParam


An application-defined parameter passed to the EnumResourceTypes or EnumResourceTypesEx function. This parameter can be used in error checking.

Return value

Type: BOOL

Returns TRUE to continue enumeration or FALSE to stop enumeration.


If IS_INTRESOURCE(lpszType) is TRUE, then lpszType specifies the integer identifier of the given resource type. Otherwise, it is a pointer to a null-terminated string. If the first character of the string is a pound sign (#), then the remaining characters represent a decimal number that specifies the integer identifier of the resource type. For example, the string "#258" represents the identifier 258.

An application must register this function by passing its address to the EnumResourceTypes or EnumResourceTypesEx function.

If the callback function returns FALSE, then EnumResourceTypes or EnumResourceTypesEx will stop enumeration and return FALSE. On Windows XP and earlier the value obtained from GetLastError will be ERROR_SUCCESS; starting with Windows Vista, the last error value will be ERROR_RESOURCE_ENUM_USER_STOP.


The libloaderapi.h header defines ENUMRESTYPEPROC as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.


Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header libloaderapi.h (include Windows.h)

See also