Övervaka förlopp med händelser

Med flera gränssnitt kan du implementera en händelsehanterare för att ta emot förloppsinformation. Till exempel kan ett händelseobjekt kopplas till dataskrivaren för att ta emot status för skrivåtgärden.

En händelsehanterare implementeras som en underrutin i ett skript. I följande exempel visas hur du definierar underrutinen och använder metoden WScript.ConnectObject för att ansluta händelsehanteraren till objektet.

    ' Create the MsftDiscFormat2Data object (see the IDiscFormat2Data interface).
    Set dataWriter = CreateObject ("IMAPI2.MsftDiscFormat2Data")

    ' Attach event handler (see the DDiscFormat2DataEvents interface).
    ' The "dwBurnEvent_" parameter identifies the handler (see the 
    ' dwBurnEvent_Update subroutine).
    WScript.ConnectObject  dataWriter, "dwBurnEvent_"

' Event handler for the MsftDiscFormat2Data.Write method.
' For details of the subroutine's parameters, see the 
' DDiscFormat2DataEvents::Update method.
SUB dwBurnEvent_Update( byRef object, byRef progress )
    ' --- Other code occurs here. 
END SUB

Namnet som anges för händelsehanterarnamnet måste innehålla understreckssuffixet ("_"). Om du vill skapa underrutinens namn sammanfogar du metodnamnet till händelsehanterarnamnet. Om du till exempel använder "dataWriterEvent_" som händelsehanterarnamn och metodnamnet är "Update" skulle underrutinens namn vara dataWriterEvent_Update.

I följande exempel visas en alternativ metod för att ansluta händelsehanteraren till objektet.

    ' Create object and connect the event handler in one step.
    '   Set dataWriter = _
    '   WScript.CreateObject("IMAPI2.MsftDiscFormat2Data","dwBurnEvent_")


' Event handler  
SUB dwBurnEvent_Update( byRef object, byRef progress )
    '--- Other code occurs here. 
END SUB

Om ett system innehåller en andra brännningsenhet att övervaka måste du skapa en annan MsftDiscFormat2Data objekt- och händelsehanterare.

Följande exempel bygger på exemplet Burning a Disc Image. Exemplet skriver en ISO-avbildning till en tom skiva och använder en händelsehanterare för att ge förloppsuppdateringar.

' This script burns data files to disc in a single session 
' using files from a single directory tree. 

' Copyright (C) Microsoft Corp. 2006

Option Explicit

' *** CD/DVD disc file system types
Const FsiFileSystemISO9660 = 1
Const FsiFileSystemJoliet  = 2
Const FsiFileSystemUDF102  = 4

' *** IFormat2Data Write Action Enumerations
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_VALIDATING_MEDIA      = 0
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_FORMATTING_MEDIA      = 1
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_INITIALIZING_HARDWARE = 2
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_CALIBRATING_POWER     = 3
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_WRITING_DATA          = 4
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_FINALIZATION          = 5
Const IMAPI_FORMAT2_DATA_WRITE_ACTION_COMPLETED             = 6
const IMAPI_FORMAT2_DATA_WRITE_ACTION_VERIFYING             = 7

WScript.Quit(Main)

Function Main
    Dim Index                ' Index to recording drive.
    Dim Recorder             ' Recorder object
    Dim Path                 ' Directory of files to burn
    Dim Stream               ' Data stream for burning device
    
    Index = 1                ' Second drive on the system
    Path = "c:\test\imt\data\2tracks"      ' Files to transfer to disc

    ' Create a DiscMaster2 object to connect to CD/DVD drives.
    Dim g_DiscMaster
    Set g_DiscMaster = WScript.CreateObject("IMAPI2.MsftDiscMaster2")

    ' Create a DiscRecorder object for the specified burning device.
    Dim uniqueId
    set recorder = WScript.CreateObject("IMAPI2.MsftDiscRecorder2")
    uniqueId = g_DiscMaster.Item(index)
    recorder.InitializeDiscRecorder( uniqueId )

    ' Create an image stream for a specified directory.
    Dim FSI                  'Disc file system
    Dim Dir                  'Root directory of the disc file system
    Dim dataWriter    
        
    ' Create a new file system image and retrieve root directory
    Set FSI = CreateObject("IMAPI2FS.MsftFileSystemImage")
    Set Dir = FSI.Root

    ' Define the new disc format and set the recorder
    Set dataWriter = CreateObject ("IMAPI2.MsftDiscFormat2Data")
    dataWriter.recorder = Recorder
    dataWriter.ClientName = "IMAPIv2 TEST"

    FSI.FreeMediaBlocks = dataWriter.FreeSectorsOnMedia
    FSI.FileSystemsToCreate = FsiFileSystemISO9660

    ' Add the directory and its contents to the file system 
    Dir.AddTree Path, false
        
    ' Create an image from the file system
    Dim result
    Set result = FSI.CreateResultImage()
    Stream = result.ImageStream
    
    ' Attach event handler to the data writing object.
    WScript.ConnectObject  dataWriter, "dwBurnEvent_"

    ' Specify the recorder and write the stream to disc.
    WScript.Echo "Writing content to disc..."
    dataWriter.write(Stream)

    WScript.Echo "----- Finished writing content -----"
    Main = 0
End Function

' Event handler - Progress updates when writing data

SUB dwBurnEvent_Update( byRef object, byRef progress )
    DIM strTimeStatus
    strTimeStatus = "Time: " & progress.ElapsedTime & _
        " / " & progress.TotalTime
   
    SELECT CASE progress.CurrentAction
    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_VALIDATING_MEDIA
        WScript.Echo "Validating media " & strTimeStatus

    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_FORMATTING_MEDIA
        WScript.Echo "Formatting media " & strTimeStatus
        
    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_INITIALIZING_HARDWARE
        WScript.Echo "Initializing Hardware " & strTimeStatus

    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_CALIBRATING_POWER
        WScript.Echo "Calibrating Power (OPC) " & strTimeStatus

    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_WRITING_DATA
        DIM totalSectors, writtenSectors, percentDone
        totalSectors = progress.SectorCount
        writtenSectors = progress.LastWrittenLba - progress.StartLba
        percentDone = FormatPercent(writtenSectors/totalSectors)
        WScript.Echo "Progress:  " & percentDone & "  " & strTimeStatus

    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_FINALIZATION
        WScript.Echo "Finishing the writing " & strTimeStatus
    
    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_COMPLETED
        WScript.Echo "Completed the burn."

    CASE IMAPI_FORMAT2_DATA_WRITE_ACTION_VERIFYING
        WScript.Echo "Verifying the data."

    CASE ELSE
        WScript.Echo "Unknown action: " & progress.CurrentAction
    END SELECT
END SUB

Relaterade ämnen

Använda IMAPI

IStream

IDiscMaster2

IDiscFormat2Data

IFileSystemImage