LEAD Technologies, Inc

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 "Visual Basic 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:
    Text Name Checked
    Native radioNative False
    Memory radioMemory False
  7. 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
  8. 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:
    Name Name
    Use Buffer Size checkBoxUseBufferSize
  9. 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:
    Property Value
    Name textBufferSize
    Name textFileName
  10. 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;
                
    
  11. Declare the following private variable:

    [Visual Basic]
                 
                Private WithEvents twnSession As TwainSession
                
    
    [C#]
                 
                private TwainSession twnSession;
                
    
  12. 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
                   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.
                      RasterSupport.SetLicense(RasterSupportType.Document, "TestKey")
                      twnSession = new TwainSession
                      twnSession.Startup(Me, "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.
                      RasterSupport.SetLicense(RasterSupportType.Document, "TestKey");
                      twnSession = new TwainSession();
                      twnSession.Startup(this, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.InitializeMultithreaded);
                   }
                   catch (Exception ex)
                   {
                      MessageBox.Show(this, ex.Message);
                   }
                }
                
    
  13. 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);
                   }
                }
                
    
  14. 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);
                   }
                }
                
    
  15. Build, and Run the program to test it.

 

 


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