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:

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 "<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.

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

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 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

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

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
               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, "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, "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: [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.