Using the Fast Twain Feature

Start Visual Studio .NET.

Choose File->New->Project… from the menu.

In the New Project dialog box, choose either "Visual C# Projects" or "Visual Basic Projects" in the Projects Type List, and choose "Windows Application " in the Templates List.

Type the project name as " UsingFastTwainFeature" in the Project Name field, and then choose OK. If desired, type a new location for your project or select a directory using the Browse button, and then choose OK .

In the "Solution Explorer" window, right-click on the "References" folder, and select "Add Reference…" from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and browse to Leadtools For .NET "\LEAD Technologies\LEADTOOLS 16.5\Bin\DotNet\Win32 " folder and select the following DLLs:

Leadtools.dll
Leadtools.Twain.dll
Leadtools.Codecs.dll
Leadtools.WinForms.dll

Click the Select button and then press the OK button to add the above DLLs to the application.

Go to the toolbox (View->Toolbox) and Drag and drop a 2 instance of RadioButton control to the top of the form and set the following properties for them:

Text	Name	Checked
Native	radioNative	False
Memory	radioMemory	False

Go to the toolbox (View->Toolbox) and Drag and drop a 1 instance of Button control to the top of the form and set the following properties for them:

Text	Name
Fast Acquire	buttonFastAcquire

Go to the toolbox (View->Toolbox) and Drag and drop a 1 instance of Check Box control to the top of the form and set the following properties for them:

Name	Name
Use Buffer Size	checkBoxUseBufferSize

Go to the toolbox (View->Toolbox) and Drag and drop a 2 instance of Text Box control to the top of the form and change the following properties:

Property	Value
Name	textBufferSize
Name	textFileName

Switch to Form1 code view (right-click Form1 in the solution explorer then select View Code ) and add the following lines at the beginning of the file:

[Visual Basic]

 
Imports Leadtools
Imports Leadtools.Twain
Imports Leadtools.Codecs
Imports Leadtools.WinForms

[C#]


using Leadtools;
using Leadtools.Twain;
using Leadtools.Codecs;
using Leadtools.WinForms;

Declare the following private variable:

[Visual Basic]

 
Private WithEvents twnSession As TwainSession

[C#]

 
private TwainSession twnSession;

Add an event handler to the Form1 Load event and code it as follows:

[Visual Basic]

 
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   Try
      ' Unlock Document support.
      ' Note that this is a sample key, which will not work in your toolkit.
      RasterSupport.Unlock(RasterSupportType.Document, "TestKey")

      twnSession = new TwainSession
      twnSession.Startup(Me, "LEAD Technologies, Inc.", "LEAD Twain .NET", "Version 14", "LEADTools Twain test sample", TwainStartupFlags.InitializeMultithreaded)
   Catch ex As Exception
      MessageBox.Show(ex.Message)
   End Try
End Sub

[C#]

 
private void Form1_Load(object sender, System.EventArgs e)
{
   try
   {
      // Unlock Document support.
      // Note that this is a sample key, which will not work in your toolkit.
      RasterSupport.Unlock(RasterSupportType.Document, "TestKey");

      twnSession = new TwainSession();
      twnSession.Startup(this, "LEAD Technologies, Inc.", "LEAD Twain .NET", "Version 14", "LEADTools Twain test sample", TwainStartupFlags.InitializeMultithreaded);
   }
   catch (Exception ex)
   {
      MessageBox.Show(this, ex.Message);
   }
}

Add an event handler to the Form1 Closing event and code it as follows:

[Visual Basic]

 
Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
   Try
      twnSession.Shutdown()
   Catch ex As Exception
      MessageBox.Show(ex.Message)
   End Try
End Sub

[C#]

 
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
   try
   {
      twnSession.Shutdown();
   }
   catch (Exception ex)
   {
      MessageBox.Show(this, ex.Message);
   }
}

Add an event handler to the buttonFastAcquire Click event and code it as follows:

[Visual Basic]

 
Private Sub buttonFastAcquire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonFastAcquire.Click
   Dim transferMode As TwainTransferMode
   Dim transferFormat As RasterImageFormat

   If radioMemory.Checked Then
      transferMode = TwainTransferMode.Buffer
      transferFormat = RasterImageFormat.CcittGroup4
   Else
      transferMode = TwainTransferMode.Native
      transferFormat = RasterImageFormat.Tif
   End If

   Try
      twnSession.AcquireFast(textFileName.Text, _
                             TwainFastUserInterfaceFlags.Show Or TwainFastUserInterfaceFlags.UseThread, _
                             transferMode, _
                             transferFormat, _
                             1, _
                             True, _
                             Convert.ToInt32(textBufferSize.Text), _
                             checkBoxUseBufferSize.Checked)
   Catch ex As Exception
      MessageBox.Show(ex.Message)
   End Try
End Sub

[C#]

 
private void buttonFastAcquire_Click(object sender, System.EventArgs e)
{
   TwainTransferMode transferMode;
   RasterImageFormat transferFormat;

   if (radioMemory.Checked)
   {
      transferMode = TwainTransferMode.Buffer;
      transferFormat = RasterImageFormat.CcittGroup4;
   }
   else
   {
      transferMode = TwainTransferMode.Native;
      transferFormat = RasterImageFormat.Tif;
   }

   try
   {
      twnSession.AcquireFast(textFileName.Text,
                             TwainFastUserInterfaceFlags.Show | TwainFastUserInterfaceFlags.UseThread,
                             transferMode,
                             transferFormat,
                             1,
                             true,
                             Convert.ToInt32(textBufferSize.Text),
                             checkBoxUseBufferSize.Checked);
   }
   catch (Exception ex)
   {
      MessageBox.Show(ex.Message);
   }
}

Build, and Run the program to test it.

	Send comments on this topic. \| Back to Introduction - All Topics \| Help Version 16.5.9.25
Using the Fast Twain Feature