CeRegEnumValue

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This function enumerates the values for the specified open registry key. CeRegEnumValue copies one indexed value name and data block for the key each time it is called.

CeRegEnumValue is a RAPI that enables an application that is running on a desktop computer to make function calls on a Microsoft® Windows® CE–based device.

STDAPI_(LONG) CeRegEnumValue( 
  HKEY hKey, 
  DWORD dwIndex, 
  LPWSTR lpszValueName, 
  LPDWORD lpcbValueName, 
  LPDWORD lpReserved, 
  LPDWORD lpType, 
  LPBYTE lpData, 
  LPDWORD lpcbData 
);

Parameters

  • hKey
    [in] Handle to a currently open key or one of the following predefined reserved handle values:

    HKEY_CLASSES_ROOT

    HKEY_CURRENT_USER

    HKEY_LOCAL_MACHINE

    HKEY_USERS

    The enumerated values are associated with the key identified by hKey.

  • dwIndex
    [in] Specifies the index of the value to retrieve. This parameter should be zero for the first call to the CeRegEnumValue function and then be incremented for subsequent calls.

    Because values are not ordered, any new value will have an arbitrary index. This means that the function may return values in any order.

  • lpszValueName
    [out] Pointer to a buffer that receives the name of the value, including the terminating null character.

  • lpcbValueName
    [in, out] Pointer to a variable that specifies the size, in characters, of the buffer pointed to by the lpValueName parameter. This size should include the terminating null character. When the function returns, the variable pointed to by lpcbValueName contains the number of characters stored in the buffer. The count returned does not include the terminating null character.

  • lpReserved
    [in] Reserved; set to NULL.

  • lpType
    [out] Pointer to a variable that receives the type code for the value entry. The type code can be one of the following values.

    Value Description
    REG_BINARY Binary data in any form.
    REG_DWORD A 32-bit number.
    REG_DWORD_LITTLE_ENDIAN A 32-bit number in little-endian format. This is equivalent to REG_DWORD.

    In little-endian format, a multi-byte value is stored in memory from the lowest byte (the "little end") to the highest byte. For example, the value 0x12345678 is stored as (0x78 0x56 0x34 0x12) in little-endian format.
    REG_DWORD_BIG_ENDIAN  A 32-bit number in big-endian format.

    In big-endian format, a multi-byte value is stored in memory from the highest byte (the "big end") to the lowest byte. For example, the value 0x12345678 is stored as (0x12 0x34 0x56 0x78) in big-endian format.
    REG_EXPAND_SZ A null-terminated string that contains unexpanded references to environment variables (for example, "%PATH%").
    REG_LINK A Unicode symbolic link. Used internally; applications should not use this type.
    REG_MULTI_SZ An array of null-terminated strings, terminated by two null characters.
    REG_NONE No defined value type.
    REG_RESOURCE_LIST A device-driver resource list.
    REG_SZ A null-terminated string.

    The lpType parameter can be NULL if the type code is not required.

  • lpData
    [out] Pointer to a buffer that receives the data for the value entry. This parameter can be NULL if the data is not required.

  • lpcbData
    [in, out] Pointer to a variable that specifies the size, in bytes, of the buffer pointed to by the lpData parameter. When the function returns, the variable pointed to by the lpcbData parameter contains the number of bytes stored in the buffer. This parameter can be NULL, only if lpData is NULL.

Return Values

ERROR_SUCCESS indicates success. A nonzero error code defined in Winerror.h indicates failure. To get a generic description of the error, call FormatMessage with the FORMAT_MESSAGE_FROM_SYSTEM flag set. The message resource is optional; therefore, if you call FormatMessage it could fail.

Remarks

To enumerate values, an application should initially call the CeRegEnumValue function with the dwIndex parameter set to zero. The application should then increment dwIndex and call the CeRegEnumValue function until there are no more values (until the function returns ERROR_NO_MORE_ITEMS).

The application can also set dwIndex to the index of the last value on the first call to the function and decrement the index until the value with index 0 is enumerated. To retrieve the index of the last value, use the CeRegQueryInfoKey function.

While using CeRegEnumValue, an application should not call any registration functions that might change the key being queried.

The key identified by the hKey parameter must have been opened with KEY_QUERY_VALUE access. To open the key, use the CeRegCreateKeyEx or CeRegOpenKeyEx function.

To determine the maximum size of the name and data buffers, use the CeRegQueryInfoKey function.

Requirements

Smartphone Platforms: Smartphone 2002 and later
OS Versions: Windows CE 3.0 and later
Header: rapi.h
Library: rapi.lib

See Also

CeRegCreateKeyEx

CeRegEnumKeyEx

CeRegOpenKeyEx

CeRegQueryInfoKey

Last updated on Friday, April 22, 2005

© 2005 Microsoft Corporation. All rights reserved.

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