Using the Fast Twain Feature

Take the following steps to start a project and to add some code that acquires the images using Fast Twain:

1. Start Visual Studio .NET.

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

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

4. 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.

5. 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 "<LEADTOOLS_INSTALLDIR>\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.

6. 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:

1. 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:

1. 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:

1. 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:

1. 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:

   VB

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

   C#

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

2. Declare the following private variable:

   VB

   Private WithEvents twnSession As TwainSession 
                    
        

   C#

   private TwainSession twnSession; 
                    
        

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

   VB

   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 
                    
        

   C#

   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); 
      } 
   } 
                    
        

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

   VB

   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); 
      } 
   } 
                    
        

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

   VB

   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); 
      } 
   } 
                    
        

6. Build, and Run the program to test it.