Public Function FindNextPrinterChangeNotification _ This is done with the Threading.RegisteredWaitHandle object: This can be used by the VB.NET Common Language Runtime to trigger a particular subroutine whenever that synchronisation object is signalled. #GET PRINTER DRIVER BY PRINTER NAME VB NET DATA WINDOWS#The FindFirstPrinterChangeNotification API call returns a Windows synchronization wait handle. NET, this is no longer necessary because it supports asynchronous events and threading. Thus, when the program was waiting for the printer notification, it was effectively locked up. In the Visual Basic 6 implementation of this, a great deal of complexity was added by the fact that it is a single-threaded system. ByVal pPrinterNotifyOptions As PrinterNotifyOptions _ Public Function FindFirstPrinterChangeNotification _ To start the printer watch, you need to pass the printer handle to FindFirstPrinterChangeNotification: ' \\ Put the field indexes in the unmanaged arrayĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_DATATYPE))ĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_DEVMODE))ĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_STATUS))ĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_DOCUMENT))ĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_PRIORITY))ĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_POSITION))ĬShort(Job_Notify_Field_Indexes.JOB_NOTIFY_FIELD_TIME))Įnd If End Sub Public Sub New( ByVal value As Printer_Notification_Types) PFields = Marshal.AllocHGlobal((JOB_FIELDS_COUNT * 2) - 1) #GET PRINTER DRIVER BY PRINTER NAME VB NET DATA FREE#' \\ Free up the global memory If pFields.ToInt32 0 ThenĮnd If If wType = Printer_Notification_Types.JOB_NOTIFY_TYPE Then Public wType As Int16 Public wReserved0 As Int16 Public dwReserved1 As Int32 Public dwReserved2 As Int32 Public FieldCount As Int32 Public pFields As IntPtr Private Sub SetupFields() In VB.NET, it is easy to translate these structures into classes that can be passed to the API, by being marshaled as if they were structures: To inform the print spooler that you want information on these fields, you create a PRINTER_NOTIFY_OPTIONS structure that is passed to FindFirstPrinterChangeNotification and which holds a pointer to an array of PRINTER_NOTIFY_OPTIONS_TYPE, one for each of the above fields that you require. JOB_NOTIFY_FIELD_SECURITY_DESCRIPTOR =
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |