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IRegistryKey::EnumerateValueKey method (portcls.h)

  • Article

The EnumerateValueKey method returns information about a registry entry that contains a value key.

Syntax

NTSTATUS EnumerateValueKey(
  [in]  ULONG                       Index,
  [in]  KEY_VALUE_INFORMATION_CLASS KeyValueInformationClass,
  [out] PVOID                       KeyValueInformation,
  [in]  ULONG                       Length,
  [out] PULONG                      ResultLength
);

Parameters

[in] Index

Specifies the subkey index. This parameter identifies the subkey whose value 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.

[in] KeyValueInformationClass

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

  • KeyValueBasicInformation
  • KeyValueFullInformation
  • KeyValuePartialInformation

[out] KeyValueInformation

Output pointer for the key value. This parameter points to a caller-allocated buffer into which the method writes the requested data. The buffer contains a structure of type KEY_VALUE_BASIC_INFORMATION, KEY_VALUE_FULL_INFORMATION, or KEY_VALUE_PARTIAL_INFORMATION, depending on the value of KeyValueInformationClass. The structure is followed by additional data whose size depends on the data type of the key value.

[in] Length

Size in bytes of the KeyValueInformation buffer, which the caller must set according to the given KeyValueInformationClass. For the call to succeed, the buffer must be at least as large as the data that the method writes into the buffer.

[out] ResultLength

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 KeyValueInformation 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

EnumerateValueKey returns STATUS_SUCCESS if the call was successful in copying the requested information into the KeyValueInformation 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 code Description
STATUS_BUFFER_TOO_SMALL
 Indicates that the specified buffer is too small to receive any information.
STATUS_INVALID_PARAMETER
 Indicates that one of the parameters passed to the method is not valid.
STATUS_NO_MORE_ENTRIES
 Indicates that no more value keys are available (the Index parameter is greater than or equal to the number of value keys).

Requirements

Requirement Value
Target Platform Universal
Header portcls.h (include Portcls.h)
IRQL PASSIVE_LEVEL

See also

IRegistryKey

KEY_VALUE_BASIC_INFORMATION

KEY_VALUE_FULL_INFORMATION

KEY_VALUE_PARTIAL_INFORMATION

ZwEnumerateValueKey