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.

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

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

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:

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

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

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:

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

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

Declare the following private variable:

            Private WithEvents twnSession As TwainSession
            

            private TwainSession twnSession;
            

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

            Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
               textFileName.Text = "c:\twain_test.tif"
               textBufferSize.Text = "2048"
               Try
                  ' Unlock Document support.
                  ' Note that this is a sample key, which will not work in your toolkit.
                  Dim MY_LICENSE_FILE As String = "d:\temp\TestLic.lic"
                  Dim MY_DEVELOPER_KEY As String = "xyz123abc"
                  RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY)
                  twnSession = new TwainSession
                  twnSession.Startup(Me.Handle, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.InitializeMultithreaded)
               Catch ex As Exception
                  MessageBox.Show(ex.Message)
               End Try
            End Sub
            

            private void Form1_Load(object sender, System.EventArgs e)
            {
               textFileName.Text = @"c:\twain_test.tif";
               textBufferSize.Text = "2048";
               try
               {
                  // Unlock Document support.
                  // Note that this is a sample key, which will not work in your toolkit.
                  string MY_LICENSE_FILE = "d:\\temp\\TestLic.lic";
                  string MY_DEVELOPER_KEY = "xyz123abc";
                  RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY);
                  twnSession = new TwainSession();
                  twnSession.Startup(this.Handle, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.InitializeMultithreaded);
               }
               catch (Exception ex)
               {
                  MessageBox.Show(this, ex.Message);
               }
            }
            

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

            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
            

            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:

            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
            

            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.