SHQueryInfoKeyA function (shlwapi.h)

Retrieves information about a specified registry key.

Syntax

LSTATUS SHQueryInfoKeyA(
  [in]            HKEY    hkey,
  [out, optional] LPDWORD pcSubKeys,
  [out, optional] LPDWORD pcchMaxSubKeyLen,
  [out, optional] LPDWORD pcValues,
  [out, optional] LPDWORD pcchMaxValueNameLen
);

Parameters

[in] hkey

Type: HKEY

A handle to the currently open key, or any of the following predefined values.

HKEY_CLASSES_ROOT

HKEY_CURRENT_CONFIG

HKEY_CURRENT_USER

HKEY_LOCAL_MACHINE

HKEY_PERFORMANCE_DATA

HKEY_USERS

[out, optional] pcSubKeys

Type: LPDWORD

The address of a DWORD that receives the number of subkeys under the specified key.

[out, optional] pcchMaxSubKeyLen

Type: LPDWORD

The address of a DWORD that receives the number of characters in the name of the subkey with the largest name.

[out, optional] pcValues

Type: LPDWORD

The address of a DWORD that receives the number of values under the specified key.

[out, optional] pcchMaxValueNameLen

Type: LPDWORD

The address of a DWORD that receives the number of characters in the name of the value with the largest name.

Return value

Type: LSTATUS

Returns ERROR_SUCCESS if successful, or a nonzero error code defined in Winerror.h otherwise. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to retrieve a textual description of the error.

Remarks

Note

The shlwapi.h header defines SHQueryInfoKey as an alias that 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 is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional, Windows XP [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header shlwapi.h
Library Shlwapi.lib
DLL Shlwapi.dll (version 4.71 or later)