NKRegQueryValueEx (Windows Embedded CE 6.0)

1/5/2010

This function retrieves the type and data for a specified value name associated with an open registry key.

Syntax

LONG NKRegQueryValueEx(
  HKEY hKey, 
  LPCWSTR lpValueName, 
  LPDWORD lpReserved, 
  LPDWORD lpType, 
  LPBYTE lpData, 
  LPDWORD lpcbData
);

Parameters

• hKey
  [in] Handle to an open key or any of the following predefined reserved handle values:

  • HKEY_CLASSES_ROOT
  • HKEY_CURRENT_USER
  • HKEY_LOCAL_MACHINE
  • HKEY_USERS

• lpValueName
  [in] Pointer to a string containing the name of the value to query.

  If this parameter is NULL or an empty string, the function retrieves the type and data for the key's unnamed value.

  A registry key does not automatically have an unnamed or default value.

  Unnamed values can be of any type.

• lpReserved
  [in] Reserved; set to NULL.

• lpType
  [out] Pointer to a variable that receives the type of data associated with the specified value.

  The following table shows the possible values that lpType can return.

  Value	Description
  REG_BINARY	Specifies a binary data in any form.
  REG_DWORD	Specifies a 32-bit number.
  REG_DWORD_LITTLE_ENDIAN	Specifies a 32-bit number in little-endian format. This is equivalent to REG_DWORD. In little-endian format, a multibyte 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	Specifies a 32-bit number in big-endian format. In big-endian format, a multibyte 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	Specifies a null-terminated string that contains unexpanded references to environment variables. For example, %PATH%.
  REG_LINK	Specifies a Unicode symbolic link. Used internally; applications should not use this type.
  REG_MULTI_SZ	Specifies an array of null-terminated strings, terminated by two null characters.
  REG_NONE	No defined value type.
  REG_RESOURCE_LIST	Specifies a device-driver resource list.
  REG_SZ	Specifies a null-terminated Unicode string.

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

• lpData
  [out] Pointer to a buffer that receives the value's data.

  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, this variable contains the size of the data copied to lpData.

  If the data has the REG_SZ, REG_MULTI_SZ or REG_EXPAND_SZ type, lpcbData also includes the size of the terminating null character.

  The lpcbData parameter can be NULL only if lpData is NULL.

  If the buffer specified by lpData parameter is not large enough to hold the data, the function returns the value ERROR_MORE_DATA, and stores the required buffer size, in bytes, into the variable pointed to by lpcbData.

  If lpData is NULL, and lpcbData is non-NULL, the function returns ERROR_SUCCESS, and stores the size of the data, in bytes, in the variable pointed to by lpcbData. This lets an application determine the best way to allocate a buffer for the value's data.

Return Value

ERROR_SUCCESS indicates success.

A nonzero error code defined in Winerror.h indicates failure.

Remarks

This function is only available for use by the OAL.

Requirements

See Also

Reference

Other OAL Functions
NKRegCreateKeyEx
NKRegOpenKeyEx
NKRegCloseKey
NKRegSetValueEx