Fires when information about a file or directory has been retrieved.
type TNotifyQueryFileInfoEvent = procedure ( Sender: TObject; const FileName: String; FileInformationClass: Integer; Buffer: Pointer; BufferLength: Integer; ValidBytes: Integer; Status: Integer; var ResultCode: Integer ) of Object;
property OnNotifyQueryFileInfo: TNotifyQueryFileInfoEvent read FOnNotifyQueryFileInfo write FOnNotifyQueryFileInfo;
This event fires when information about the file or directory specified by FileName has been retrieved; typically in response to the Windows API's NtQueryInformationFile function.
The FileInformationClass parameter indicates what kind of file information was requested. Please refer to the NtQueryInformationFile function's documentation for more information about possible values.
The Buffer parameter points to a memory buffer that, if the request was successful, contains the requested file information. The BufferLength and ValidBytes parameters reflect the capacity of Buffer and the length of the data it contains (respectively), in bytes; ValidBytes may be less than BufferLength. Please refer to the Buffer Parameters topic for more information on how to work with memory buffer event parameters.
The format of the data itself is determined by the specified FileInformationClass; please refer to the NtQueryInformationFile function's documentation for more information.
The Status parameter contains an NT status code that indicates the outcome of the operation; 0 indicates success. To convert this value to a Win32 error code, call the NtStatusToWin32Error method. Please note that this event won't fire for failed requests unless the ProcessFailedRequests property is enabled.
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, set it to a non-zero value to report an appropriate error. Note, however, that this event fires after the operation has already completed, so reporting an error won't actually affect the operation itself. Please refer to the Error Reporting and Handling topic for more information.
This event is fired asynchronously; please refer to the Event Types topic for more information.