Unzip with Progress Monitoring Event Callbacks

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VB.NET sample program demonstrating the unzip progress monitoring event callbacks available with the Chilkat Zip component.

    ' When using events, we must declare the variable as a global or
    ' class member WithEvents
    ' Once it is declared, we can select the "zip" object from 
    ' the VB.NET IDE to see the events.  If you select the event
    ' from the dropdown, Visual Studio will create the callback
    ' subroutine for you.
    Dim WithEvents zip As New Chilkat.Zip()

    ' Unzip with progress monitoring callbacks.
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        ' This must be called once at the beginning of your program.
        zip.UnlockComponent("Anything for 30-day trial")
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        ' Don't forget to enable events.
        zip.EnableEvents = True

        ' Open a zip archive.
        Dim success As Boolean
        success = zip.OpenZip("myZip.zip")
        If (Not success) Then
            MessageBox.Show(zip.LastErrorText)
            Exit Sub
        End If

        Dim dirPath As String
        Dim numFilesUnzipped As Integer
        dirPath = "./myZip"
        ' Unzip to a sub-directory relative to the current working directory
        ' of the calling process.  If the myZip directory does not exist,
        ' it is automatically created.
        numFilesUnzipped = zip.Unzip(dirPath)
        If (numFilesUnzipped < 0) Then
            MessageBox.Show(zip.LastErrorText)
            Exit Sub
        End If

        zip.CloseZip()

    End Sub

    ' When unzipping large Zips, there may be a long time between percent-done callbacks.
    ' The OnAbortCheck callback is called about once every .5 seconds that elapse without
    ' a percent-done callback.
    Private Sub zip_OnAbortCheck(ByVal sender As Object, ByVal args As Chilkat.AbortCheckEventArgs) Handles zip.OnAbortCheck
        ' To abort the unzipping, set args.Abort = true:
        ' if (....) then
        '      args.Abort = True
        ' end if
    End Sub

    ' Called during unzipping to monitor the percentage progress to completion.
    Private Sub zip_OnUnzipPercentDone(ByVal sender As Object, ByVal args As Chilkat.UnzipPercentDoneEventArgs) Handles zip.OnUnzipPercentDone
        ' args contains two members:
        ' args.Abort: Set this boolean flag to force the unzip to abort.
        ' args.PercentDone: Contains an integer having a value between 1 and 100.
        ProgressBar1.Value = args.PercentDone

        ' The following commented-out lines will abort the unzip after it is 50% complete. 
        'If (args.PercentDone >= 50) Then
        '    args.Abort = True
        'End If
    End Sub

    ' Called during the unzip process for each file before it is to be unzipped.
    Private Sub zip_OnToBeUnzipped(ByVal sender As Object, ByVal args As Chilkat.ToBeUnzippedEventArgs) Handles zip.OnToBeUnzipped
        ' args contains five members:
        ' args.Exclude: You may set this to true to prevent the file from being unzipped.
        ' args.CompressedSize: The compressed size in bytes.
        ' args.FileSize: The original uncompressed size of the file.
        ' args.FileName: The filename.
        ' args.IsDirectory: True if the filename is a directory, false otherwise.
        If (args.IsDirectory) Then
            ListBox1.Items.Add("DIR: " + args.FileName)
        Else
            ListBox1.Items.Add(args.FileName)
        End If
    End Sub

    ' Called once for each file after it is unzipped.
    Private Sub zip_OnFileUnzipped(ByVal sender As Object, ByVal args As Chilkat.FileUnzippedEventArgs) Handles zip.OnFileUnzipped
        ' args contains five members:
        ' args.Abort: You may set this to true to abort the unzip process.
        ' args.CompressedSize: The compressed size in bytes.
        ' args.FileSize: The original uncompressed size of the file.
        ' args.FileName: The filename.
        ' args.IsDirectory: True if the filename is a directory, false otherwise.
        If (args.IsDirectory) Then
            ListBox2.Items.Add("DIR: " + args.FileName)
        Else
            ListBox2.Items.Add(args.FileName)
        End If

    End Sub

    ' Called once at the very beginning of an unzip.
    Private Sub zip_OnUnzipBegin(ByVal sender As Object, ByVal args As System.EventArgs) Handles zip.OnUnzipBegin

    End Sub

    ' Called once at the very end of an unzip.
    Private Sub zip_OnUnzipEnd(ByVal sender As Object, ByVal args As System.EventArgs) Handles zip.OnUnzipEnd

    End Sub