Progress Event

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Forms.DocumentWriters 
 
       
Public Sub DocumentWriterProgressExample() 
   ' Get the input and output file names to use 
   Dim inputFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Leadtools.docx") 
   Dim outputFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Example.pdf") 
   ' Show the progress dialog 
   Using dlg As New MyProgressDialog(inputFileName, outputFileName) 
      If dlg.ShowDialog() = DialogResult.OK Then 
         MessageBox.Show("Done!") 
      Else 
         MessageBox.Show("User has canceled the operation or an error occurred.") 
      End If 
   End Using 
End Sub 
 
' Dialog box to show the  
Private Class MyProgressDialog 
   Inherits Form 
   ' Files 
   Private _inputFileName As String 
   Private _outputFileName As String 
 
   ' The controls on the dialog 
   Private _descriptionLabel As Label 
   Private _progressBar As ProgressBar 
   Private _cancelButton As Button 
 
   ' Has the operation been canceled? 
   Private _isCancelPending As Boolean 
   ' Is the dialog working? 
   Private _isWorking As Boolean 
 
   Public Sub New(inputFileName As String, outputFileName As String) 
      InitializeComponent() 
 
      _inputFileName = inputFileName 
      _outputFileName = outputFileName 
      _isCancelPending = False 
      _isWorking = True 
   End Sub 
 
   Protected Overrides Sub OnLoad(ByVal e As EventArgs) 
      ' To keep the UI functioning, do the conversion in a separate thread 
      BeginInvoke(New MethodInvoker(AddressOf DoWork)) 
 
      MyBase.OnLoad(e) 
   End Sub 
 
   Private Sub DoWork() 
      Dim docWriter As DocumentWriter 
      Dim operation As String = String.Empty 
 
      Dim progressHandler As EventHandler(Of DocumentProgressEventArgs) = _ 
         Sub(sender As Object, e As DocumentProgressEventArgs) 
            ' Update the description label progress bar 
            _descriptionLabel.Text = operation 
            _progressBar.Value = e.Percentage 
 
            ' Check if the user clicked the Cancel button, if so, abort the operation 
            If (_isCancelPending) Then 
               e.Cancel = True 
            End If 
 
            Application.DoEvents() 
         End Sub 
 
      ' Get the number of pages 
      Dim codecs As New RasterCodecs() 
      codecs.Options.RasterizeDocument.Load.Resolution = 300 
      Dim pageCount As Integer = codecs.GetTotalPages(_inputFileName) 
 
      ' Create the document writer 
      docWriter = New DocumentWriter() 
 
      ' Create the document 
      operation = "Creating the document..." 
 
      ' Subscribe to the progress event 
      AddHandler docWriter.Progress, progressHandler 
      docWriter.BeginDocument(_outputFileName, DocumentFormat.Pdf) 
 
      ' Add the pages 
      For pageNumber As Integer = 1 To pageCount 
 
         If _isCancelPending Then 
            Exit For 
         End If 
 
         ' Load the page as SVG 
         Dim page As New DocumentSvgPage() 
         page.SvgDocument = codecs.LoadSvg(_inputFileName, pageNumber, Nothing) 
 
         ' Add the page, notice we will not be using image/text feature (the default) 
         operation = String.Format("Adding page {0} of {1}...", pageNumber, pageCount) 
         docWriter.AddPage(page) 
 
         ' Delete the SVG 
         page.SvgDocument.Dispose() 
      Next 
 
      ' Finally finish writing the PDF file on disk 
      operation = "Finishing the document..." 
      docWriter.EndDocument() 
 
      ' Remove the progress handler 
      RemoveHandler docWriter.Progress, progressHandler 
 
      codecs.Dispose() 
 
      ' Set the dialog results based on whether the user has canceled the operation 
      If _isCancelPending Then 
         DialogResult = DialogResult.Cancel 
      Else 
         DialogResult = DialogResult.OK 
      End If 
 
      ' The dialog can be closed now 
      _isWorking = False 
 
      ' We are done 
      Close() 
   End Sub 
 
   Private Sub _cancelButton_Click(sender As Object, e As EventArgs) 
      ' Set the isCanceled variable to true, this will break from the 
      ' progress callback and closes the dialog 
      _isCancelPending = True 
   End Sub 
 
   Protected Overrides Sub OnFormClosing(ByVal e As FormClosingEventArgs) 
      ' Dont allow the form to close while the callback is still working 
      ' Instead, cancel the operation 
      If _isWorking Then 
         e.Cancel = True 
      End If 
 
      MyBase.OnFormClosing(e) 
   End Sub 
 
   Private Sub InitializeComponent() 
      ' Create the controls in this form, a text label, a progress bar and a cancel button 
      SuspendLayout() 
 
      ' Text label 
      _descriptionLabel = New Label() 
      _descriptionLabel.Location = New Point(26, 21) 
      _descriptionLabel.Name = "_descriptionLabel" 
      _descriptionLabel.Size = New Size(367, 23) 
      _descriptionLabel.TabIndex = 0 
      _descriptionLabel.TextAlign = ContentAlignment.MiddleLeft 
      _descriptionLabel.Text = "Creating final document..." 
 
      ' Progress bar 
      _progressBar = New ProgressBar() 
      _progressBar.Location = New Point(27, 47) 
      _progressBar.Name = "_progressBar" 
      _progressBar.Size = New Size(364, 23) 
      _progressBar.TabIndex = 1 
 
      ' Cancel button 
      _cancelButton = New Button() 
      _cancelButton.DialogResult = DialogResult.Cancel 
      _cancelButton.Location = New Point(172, 76) 
      _cancelButton.Name = "_cancelButton" 
      _cancelButton.Size = New Size(75, 23) 
      _cancelButton.TabIndex = 2 
      _cancelButton.Text = "Cancel" 
      _cancelButton.UseVisualStyleBackColor = True 
      AddHandler _cancelButton.Click, AddressOf _cancelButton_Click 
 
      ' Add the controls 
      Controls.Add(_descriptionLabel) 
      Controls.Add(_progressBar) 
      Controls.Add(_cancelButton) 
 
      ' Initialize the dialog 
      AutoScaleDimensions = New SizeF(6.0F, 13.0F) 
      AutoScaleMode = AutoScaleMode.Font 
      CancelButton = _cancelButton 
      ClientSize = New Size(420, 118) 
      FormBorderStyle = FormBorderStyle.FixedDialog 
      MaximizeBox = False 
      MinimizeBox = False 
      Name = "MyProgressDialog" 
      ShowInTaskbar = False 
      StartPosition = FormStartPosition.CenterParent 
      Text = "DocumentWriter Progress Example" 
 
      ResumeLayout() 
   End Sub 
End Class