RegCloseKey

The RegCloseKey function releases a handle to the specified key.

LONG RegCloseKey(
  HKEY hKey   // handle to key to close
);
 

Parameters

hKey
Handle to the open key to close.

Return Values

If the function succeeds, the return value is ERROR_SUCCESS.

If the function fails, the return value is a nonzero error code defined in WINERROR.H. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error.

Remarks

The handle for a specified key should not be used after it has been closed, because it will no longer be valid. Key handles should not be left open any longer than necessary.

The RegCloseKey function does not necessarily write information to the registry before returning; it can take as much as several seconds for the cache to be flushed to the hard disk. If an application must explicitly write registry information to the hard disk, it can use the RegFlushKey function. RegFlushKey, however, uses many system resources and should be called only when necessary.

Windows CE: The RegCloseKey function always writes information to the registry before returning, eliminating the need to flush keys in the Windows CE registry.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winreg.h.
  Import Library: Use advapi32.lib.

See Also

Registry Overview, Registry Functions, RegCreateKey, RegCreateKeyEx, RegDeleteKey, RegFlushKey, RegOpenKey, RegOpenKeyEx, RegSetValue, RegSetValueEx