RegQueryMultipleValues

The RegQueryMultipleValues function retrieves the type and data for a list of value names associated with an open registry key. 

LONG RegQueryMultipleValues(
  HKEY hKey,         // handle to key to query
  PVALENT val_list,  // pointer to array of value entry structures
  DWORD num_vals,    // size of array of value entry structures
  LPTSTR lpValueBuf, // pointer to buffer for value information
  LPDWORD ldwTotsize // pointer to size of value buffer
);

Parameters

hKey
Handle to a currently open key or any of the pre-defined reserved handle values:

HKEY_CLASSES_ROOT
HKEY_CURRENT_CONFIG
HKEY_CURRENT_USER
HKEY_LOCAL_MACHINE
HKEY_USERS
Windows NT: HKEY_PERFORMANCE_DATA
Windows 95 and Windows 98: HKEY_DYN_DATA

val_list
Pointer to an array of VALENT structures that describe one or more value entries. On input, the ve_valuename member of each structure must contain a pointer to the name of a value to retrieve. The function fails if any of the specified values do not exist in the specified key.

If the function succeeds, each element of the array contains the information for the specified value.

num_vals
Specifies the number of elements in the val_list array.
lpValueBuf
Pointer to a buffer. If the function succeeds, the buffer receives the data for each value.

If lpValueBuf is NULL, the function returns success, and ldwTotsize returns the required size, in bytes, of the buffer.

ldwTotsize
Pointer to a value that specifies the size, in bytes, of the buffer pointed to by the lpValueBuf parameter. If the function succeeds, ldwTotsize returns the number of bytes copied to the buffer. If the function fails because the buffer is too small, ldwTotsize receives the required size, in bytes.

Return Values

If the function succeeds, the return value is ERROR_SUCCESS.

If the function fails, the return value is one of the following error codes:

Value Meaning
ERROR_CANTREAD RegQueryMultipleValues cannot instantiate or access the provider of the dynamic key.
ERROR_MORE_DATA The buffer pointed to by lpValueBuf was too small. In this case, ldwTotsize returns the required buffer size.
ERROR_TRANSFER_TOO_LONG The total length of the requested data (size of the val_list array + ldwTotSize) is more than the system limit of one megabyte.

Remarks

The RegQueryMultipleValues function allows an application to query one or more values of a static or dynamic key. If the target key is a static key, the system provides all of the values in an atomic fashion. To prevent excessive serialization, the aggregate data returned by the function can not exceed one megabyte.

If the target key is a dynamic key, its provider must provide all the values in an atomic fashion. This means the provider should fill the results buffer synchronously, providing a consistent view of all the values in the buffer while avoiding excessive serialization. The provider can provide at most one megabyte of total output data during an atomic call to this function.

RegQueryMultipleValues is supported remotely; that is, the hKey parameter passed to the function can refer to a remote computer.

QuickInfo

  Windows NT: Requires version 3.5 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in winreg.h.
  Import Library: Use kernel32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT.

See Also

Registry Overview, Registry Functions, VALENT