Monitoramento do progresso com eventos

Várias interfaces permitem implementar um manipulador de eventos para receber informações de progresso. Por exemplo, um objeto de evento pode ser anexado ao gravador de dados para receber o status da operação de gravação.

Um manipulador de eventos é implementado como uma sub-rotina em um script. O exemplo a seguir mostra como definir a sub-rotina e usar o método WScript.ConnectObject para conectar o manipulador de eventos ao objeto.

    ' 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

O nome especificado para o nome do manipulador de eventos deve conter o sufixo de sublinhado ("_"). Para formar o nome da sub-rotina, concatene o nome do método ao nome do manipulador de eventos. Por exemplo, se você usar "dataWriterEvent_" como o nome do manipulador de eventos e o nome do método for "Atualizar", o nome da sub-rotina será dataWriterEvent_Update.

O exemplo a seguir mostra uma abordagem alternativa para conectar o manipulador de eventos ao objeto.

    ' 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

Se um sistema contiver um segundo dispositivo de queima para monitorar, você precisará criar outro objeto MsftDiscFormat2Data e um manipulador de eventos.

O exemplo a seguir baseia-se no exemplo Queimando uma Imagem de Disco . O exemplo grava uma imagem ISO em um disco em branco e usa um manipulador de eventos para fornecer atualizações de progresso.

' 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

Tópicos relacionados

Usando IMAPI

IStream

IDiscMaster2

IDiscFormat2Data

IFileSystemImage