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4/8/2010

This function retrieves the type and data for a specified value name associated with an open registry key on a remote Windows Embedded CE–based device.

Syntax 

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

Parameters

hKey

[in] Handle to a currently 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 lpTypecan returnThe value returned through this parameter will be one of the following.

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 lpTypeparameter 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 lpDataparameter. 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, then lpcbDatawill also include the size of the terminating null character.

  • The lpcbDataparameter can be NULL only if lpDatais NULL.

  • If the buffer provided in the lpDataparameter 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 lpDatais NULL, and lpcbDatais 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. To get a generic description of the error, call FormatMessagewith the FORMAT_MESSAGE_FROM_SYSTEM flag set.

Remarks

The key identified by hKeymust have been opened with KEY_QUERY_VALUE access. To open the key, use the CeRegCreateKeyExor CeRegOpenKeyExfunction.

Windows Embedded CE only supports the Unicode version of this function.

Note:
On devices running Windows Mobile 2003 Second Edition, if the buffer provided in the lpDataparameter is not large enough to hold the returned data, the required buffer size is not returned in the lpcbDataparameter and the function returns the error code 0x80004005.

Requirements

Header rapi.h
Library rapi.lib
Windows Embedded CE Windows CE 3.0 and later
Windows Mobile Pocket PC 2002 and later, Smartphone 2002 and later

See Also