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 "\LEAD Technologies\LEADTOOLS xx\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.
                  RasterSupport.Unlock(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.Unlock(RasterSupportType.Document, "TestKey");
                  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.

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Using the Fast Twain Feature