The RegCreateKeyEx function creates the specified registry key. If the key already exists, the function opens it.
LONG RegCreateKeyEx( HKEY hKey, // handle to open key LPCTSTR lpSubKey, // subkey name DWORD Reserved, // reserved LPTSTR lpClass, // class string DWORD dwOptions, // special options REGSAM samDesired, // desired security access LPSECURITY_ATTRIBUTES lpSecurityAttributes, // inheritance PHKEY phkResult, // key handle LPDWORD lpdwDisposition // disposition value buffer );
Windows NT/2000: HKEY_PERFORMANCE_DATA
Windows 95/98: HKEY_DYN_DATA
The key opened or created by the RegCreateKeyEx function is a subkey of the key identified by the hKey parameter.
Windows NT/2000: The subkey name specified by lpSubKey must not begin with the backslash character ('\'). If it does, ERROR_BAD_PATHNAME is returned.
Windows 95/98: Beginning backslash characters in the subkey name specified by lpSubKey are ignored.
|REG_OPTION_NON_VOLATILE||This key is not volatile; this is the default. The information is stored in a file and is preserved when the system is restarted. The RegSaveKey function saves keys that are not volatile.|
|REG_OPTION_VOLATILE||Windows NT/2000: All keys created by the function are volatile. The information is stored in memory and is not preserved when the corresponding registry hive is unloaded. For HKEY_LOCAL_MACHINE, this occurs when the system is shut down. For registry keys loaded by the RegLoadKey function, this occurs when the corresponding RegUnloadKey is performed. The RegSaveKey function does not save volatile keys. This flag is ignored for keys that already exist.
Windows 95: This value is ignored. If REG_OPTION_VOLATILE is specified, the RegCreateKeyEx function creates nonvolatile keys and returns ERROR_SUCCESS.
|REG_OPTION_BACKUP_RESTORE||Windows NT/2000: If this flag is set, the function ignores the samDesired parameter and attempts to open the key with the access required to backup or restore the key. If the calling thread has the SE_BACKUP_NAME privilege enabled, the key is opened with ACCESS_SYSTEM_SECURITY and KEY_READ access. If the calling thread has the SE_RESTORE_NAME privilege enabled, the key is opened with ACCESS_SYSTEM_SECURITY and KEY_WRITE access. If both privileges are enabled, the key has the combined accesses for both privileges.|
|KEY_CREATE_LINK||Permission to create a symbolic link.|
|KEY_CREATE_SUB_KEY||Permission to create subkeys.|
|KEY_ENUMERATE_SUB_KEYS||Permission to enumerate subkeys.|
|KEY_EXECUTE||Permission for read access.|
|KEY_NOTIFY||Permission for change notification.|
|KEY_QUERY_VALUE||Permission to query subkey data.|
|KEY_SET_VALUE||Permission to set subkey data.|
|KEY_ALL_ACCESS||Combines the KEY_QUERY_VALUE, KEY_ENUMERATE_SUB_KEYS, KEY_NOTIFY, KEY_CREATE_SUB_KEY, KEY_CREATE_LINK, and KEY_SET_VALUE access rights, plus all the standard access rights except SYNCHRONIZE.|
|KEY_READ||Combines the STANDARD_RIGHTS_READ, KEY_QUERY_VALUE, KEY_ENUMERATE_SUB_KEYS, and KEY_NOTIFY access rights.|
|KEY_WRITE||Combines the STANDARD_RIGHTS_WRITE, KEY_SET_VALUE, and KEY_CREATE_SUB_KEY access rights.|
Windows NT/2000: The lpSecurityDescriptor member of the structure specifies a security descriptor for the new key. If lpSecurityAttributes is NULL, the key gets a default security descriptor.
|REG_CREATED_NEW_KEY||The key did not exist and was created.|
|REG_OPENED_EXISTING_KEY||The key existed and was simply opened without being changed.|
If lpdwDisposition is NULL, no disposition information is returned.
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.
The key that the RegCreateKeyEx function creates has no values. An application can use the RegSetValue or RegSetValueEx function to set key values.
The key identified by the hKey parameter must have been opened with KEY_CREATE_SUB_KEY access. To open the key, use the RegCreateKeyEx or RegOpenKeyEx function.
An application cannot create a key that is a direct child of HKEY_USERS or HKEY_LOCAL_MACHINE. An application can create subkeys in lower levels of the HKEY_USERS or HKEY_LOCAL_MACHINE trees.
An application can use RegCreateKeyEx to temporarily lock a portion of the registry. When the locking process creates a new key, it receives the disposition value REG_CREATED_NEW_KEY, indicating that it "owns" the lock. Another process attempting to create the same key receives the disposition value REG_OPENED_EXISTING_KEY, indicating that another process already owns the lock.
Windows 95/98: No registry subkey or value name may exceed 255 characters.
Windows NT/2000: Requires Windows NT 3.1 or later.
Windows 95/98: Requires Windows 95 or later.
Header: Declared in Winreg.h; include Windows.h.
Library: Use Advapi32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.
Registry Overview, Registry Functions, RegCloseKey, RegCreateKey, RegDeleteKey, RegOpenKey, RegOpenKeyEx, RegSaveKey, SECURITY_ATTRIBUTES