on_before_query_key Event
Fires before a registry key's information is retrieved.
Syntax
class CBRegistryBeforeQueryKeyEventParams(object): @property def key_context() -> int: ... @property def requested_fields() -> int: ... @property def last_write_time() -> datetime.datetime: ... @last_write_time.setter def last_write_time(value) -> None: ... @property def name() -> str: ... @name.setter def name(value) -> None: ... @property def class_name() -> str: ... @class_name.setter def class_name(value) -> None: ... @property def sub_keys() -> int: ... @sub_keys.setter def sub_keys(value) -> None: ... @property def max_name_length() -> int: ... @max_name_length.setter def max_name_length(value) -> None: ... @property def max_class_name_length() -> int: ... @max_class_name_length.setter def max_class_name_length(value) -> None: ... @property def values() -> int: ... @values.setter def values(value) -> None: ... @property def max_value_name_length() -> int: ... @max_value_name_length.setter def max_value_name_length(value) -> None: ... @property def max_value_data_size() -> int: ... @max_value_data_size.setter def max_value_data_size(value) -> None: ... @property def virtualization_candidate() -> bool: ... @virtualization_candidate.setter def virtualization_candidate(value) -> None: ... @property def virtualization_enabled() -> bool: ... @virtualization_enabled.setter def virtualization_enabled(value) -> None: ... @property def virtual_target() -> bool: ... @virtual_target.setter def virtual_target(value) -> None: ... @property def virtual_store() -> bool: ... @virtual_store.setter def virtual_store(value) -> None: ... @property def virtual_source() -> bool: ... @virtual_source.setter def virtual_source(value) -> None: ... @property def processed() -> bool: ... @processed.setter def processed(value) -> None: ... @property def fire_after_event() -> bool: ... @fire_after_event.setter def fire_after_event(value) -> None: ... @property def stop_filtering() -> bool: ... @stop_filtering.setter def stop_filtering(value) -> None: ... @property def result_code() -> int: ... @result_code.setter def result_code(value) -> None: ... # In class CBRegistry: @property def on_before_query_key() -> Callable[[CBRegistryBeforeQueryKeyEventParams], None]: ... @on_before_query_key.setter def on_before_query_key(event_hook: Callable[[CBRegistryBeforeQueryKeyEventParams], None]) -> None: ...
Remarks
This event fires before a registry key's information is retrieved.
Applications only need to handle this event if they've added a standard filter rule that includes the REG_CE_BEFORE_QUERY_KEY flag.
The KeyContext parameter is a placeholder for application-defined data associated with the registry key. Please refer to the Contexts topic for more information. Note that this event does not expose the registry key's name for performance reasons; applications that need it should store it in KeyContext during the on_before_create_key/on_before_open_key event so that it can be retrieved when this event fires.
The RequestedFields parameter indicates which pieces of information about the key were requested. The value of this parameter is a combination of one or more of the following:
REG_KEYFIELD_LASTWRITETIME | 1 | A registry key's last write time. |
REG_KEYFIELD_NAME | 2 | A registry key's name. |
REG_KEYFIELD_MAXNAMELENGTH | 4 | A registry key's longest subkey name. |
REG_KEYFIELD_CLASSNAME | 8 | A registry key's class name. |
REG_KEYFIELD_MAXCLASSNAMELENGTH | 16 | A registry key's longest subkey class name. |
REG_KEYFIELD_SUBKEYS | 32 | The number of subkeys a registry key has. |
REG_KEYFIELD_VALUES | 64 | The number of values a registry key has. |
REG_KEYFIELD_MAXVALUENAMELENGTH | 128 | A registry key's longest value name. |
REG_KEYFIELD_MAXVALUEDATASIZE | 256 | A registry key's largest value data size. |
REG_KEYFIELD_VIRTUALIZATIONINFO | 512 | A registry key's virtualization information. |
The LastWriteTime parameter specifies when the key was last changed, specified in UTC.
The Name parameter specifies the key's name. The maximum length of a registry key name is 255 characters.
The ClassName parameter specifies the key's class name. The maximum length of a registry key class name is 255 characters.
The SubKeys parameter specifies the number of subkeys that the key has.
The MaxNameLength parameter specifies the length, in bytes, of the key's longest subkey name.
The MaxClassNameLength parameter specifies the length, in bytes, of the key's longest subkey class name.
The Values parameter specifies the number of values the key has.
The MaxValueNameLength parameter specifies the length, in bytes, of the key's longest value name.
The MaxValueDataSize parameter specifies the length, in bytes, of the subkey's largest value data size.
The VirtualizationCandidate parameter specifies whether the key is part of the virtualization namespace scope.
The VirtualizationEnabled parameter specifies whether virtualization is enabled on the key. This parameter can only be True if VirtualizationCandidate is True.
The VirtualTarget parameter specifies whether the key is a virtual key. This parameter can only be True if both VirtualizationCandidate and VirtualizationEnabled are both False; and its value is only valid on virtual store key handles.
The VirtualStore parameter specifies whether the key is part of the virtual store path.
The VirtualSource parameter specifies whether the key has ever been virtualized. This parameter can only be True if VirtualizationCandidate is True.
The Processed parameter indicates whether the underlying request has been handled successfully. Applications should set this parameter to True if they've handled the request themselves (this will prevent the corresponding After* event from being called). Note that this parameter's value is ignored if an error is returned via ResultCode.
The FireAfterEvent parameter specifies whether the corresponding After* event should be fired; it is True by default. Note that, regardless of how this parameter is set, the corresponding After* event will not fire if Processed is True, or if an error code is returned via ResultCode.
The StopFiltering parameter specifies whether the class's system driver should ignore all further operations for the registry key; it is False by default. Applications may set this parameter to True to prevent any further events from firing for the registry key.
The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource isn't available, security checks failed, etc.), set it to a non-zero value to report an appropriate error. Please refer to the Error Reporting and Handling topic for more information.
This event is fired synchronously; please refer to the Event Types topic for more information.