IRegistryKey::EnumerateKey method

The EnumerateKey method returns information about the subkeys of the open key.


NTSTATUS EnumerateKey(
  [in]   ULONG Index,
  [in]   KEY_INFORMATION_CLASS KeyInformationClass,
  [out]  PVOID KeyInformation,
  [in]   ULONG Length,
  [out]  PULONG ResultLength


Index [in]

Specifies the subkey index. This parameter identifies the subkey for which key information is requested. If the key contains n subkeys, valid indices range from 0 to n-1. If the index exceeds this range, the method returns STATUS_NO_MORE_ENTRIES.

KeyInformationClass [in]

Specifies the type of information to be returned in the buffer. Set this parameter to one of the following KEY_INFORMATION_CLASS enumeration values:

  • KeyBasicInformation

  • KeyFullInformation

  • KeyNodeInformation

KeyInformation [out]

Pointer to the key information buffer. This parameter points to a caller-allocated buffer into which the method writes the requested data. The buffer contains a structure of type KEY_BASIC_INFORMATION, KEY_FULL_INFORMATION, or KEY_NODE_INFORMATION, depending on the value of KeyInformationClass. The structure is followed by a string of Unicode characters whose size depends on the type of information being requested about the key.

Length [in]

Specifies the size in bytes of the KeyInformation buffer, which the caller must set according to the given KeyInformationClass. For the call to succeed, the buffer must be at least as large as the data that the method writes into the buffer.

ResultLength [out]

Output pointer for the length of the resulting data. This parameter points to a caller-allocated ULONG variable into which the method writes a count specifying the number of bytes actually written into the KeyInformation buffer. If the specified buffer length is too small to contain the information, however, the method instead outputs the required buffer size and returns STATUS_BUFFER_OVERFLOW.

Return value

EnumerateKey returns STATUS_SUCCESS if the call was successful in retrieving the requested information in the KeyInformation buffer. If the specified buffer size is too small to receive all of the available information, the method returns STATUS_BUFFER_OVERFLOW. Otherwise, the method returns an appropriate error code. The following table shows some of the possible return status codes.

Return codeDescription

Indicates that the specified buffer is too small to receive any information.


Indicates that no more subkeys are available (subkey index is larger than or equal to the number of subkeys).





Portcls.h (include Portcls.h)



See also




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