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Twain Feeder Tutorial # 2
Take the following steps to start a project:
  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 "TwainFeeder2" 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 "\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.
  6. 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
    Acquire buttonAcquire
  7. 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;
                
    
  8. Declare the following private variable:

    [Visual Basic]

                Private WithEvents twnSession As TwainSession
                
    
    [C#]
                private TwainSession twnSession;
                
    
  9. 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
                   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.None)
                   Catch ex As Exception
                      MessageBox.Show(ex.Message)
                   End Try
                End Sub   
                
    
    [C#]
                private void Form1_Load(object sender, System.EventArgs e)
                {
                   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.None);
                   }
                   catch (Exception ex)
                   {
                      MessageBox.Show(this, ex.Message);
                   }
                }
                
    
  10. Add an event handler to the Form1 Closing event and code it as follows:

    [Visual Basic]

                 
                Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.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);
                   }
                }
                
    
  11. Add an event handler to the buttonAcquire Click event and code it as follows:

    [Visual Basic]

                Private Sub buttonAcquire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonAcquire.Click
                   Dim twainCap As TwainCapability = New TwainCapability
                   
                   twnSession.SelectSource(String.Empty)
                   
                   Try
                      twainCap.Information.Type = TwainCapabilityType.FeederEnabled
                      twainCap.Information.ContainerType = TwainContainerType.OneValue
                      
                      Dim enable As Boolean = True
                      twainCap.OneValueCapability.ItemType = TwainItemType.Bool
                      twainCap.OneValueCapability.Value = enable
                      
                      twnSession.SetCapability(twainCap, TwainSetCapabilityMode.Set)
                      MessageBox.Show(Me, "CAP_FEEDERENABLED capability is enabled")
                      
                      ' check if there is document loaded in the feeder
                      twainCap = twnSession.GetCapability(TwainCapabilityType.FeederLoaded, TwainGetCapabilityMode.GetValues)
                      ' check if the selected driver supports duplex capability
                      enable = CType(twainCap.OneValueCapability.Value, Boolean)
                      If enable Then
                         MessageBox.Show(Me, "There is document loaded in the feeder")
                      Else
                         MessageBox.Show(Me, "There is no document loaded in the feeder")
                      End If
                   Catch ex As Exception
                      MessageBox.Show(Me, ex.Message)
                   End Try
                   
                   ' try to acquire pages using CAP_FEEDERENABLED and CAP_FEEDERLOADED capabilities
                   twnSession.Acquire(TwainUserInterfaceFlags.Show Or TwainUserInterfaceFlags.Modal)
                End Sub
                
    
    [C#]
                private void buttonAcquire_Click(object sender, System.EventArgs e)
                {
                   TwainCapability twainCap = new TwainCapability();
                   twnSession.SelectSource(string.Empty);
                   
                   try
                   {
                      twainCap.Information.Type = TwainCapabilityType.FeederEnabled;
                      twainCap.Information.ContainerType = TwainContainerType.OneValue;
                      
                      bool enable = true;
                      twainCap.OneValueCapability.ItemType = TwainItemType.Bool;
                      twainCap.OneValueCapability.Value = enable;
                      
                      twnSession.SetCapability(twainCap, TwainSetCapabilityMode.Set);
                      MessageBox.Show(this, "CAP_FEEDERENABLED capability is enabled");
                      
                      // check if there is document loaded in the feeder
                      twainCap = twnSession.GetCapability(TwainCapabilityType.FeederLoaded, TwainGetCapabilityMode.GetValues);
                      // check if the selected driver supports duplex capability
                      enable = (bool)twainCap.OneValueCapability.Value;
                      if (enable)
                         MessageBox.Show(this, "There is document loaded in the feeder");
                      else
                         MessageBox.Show(this, "There is no document loaded in the feeder");
                   }
                   catch (Exception ex)
                   {
                      MessageBox.Show(this, ex.Message);
                   }
                   
                   // try to acquire pages using CAP_FEEDERENABLED and CAP_FEEDERLOADED capabilities
                   twnSession.Acquire(TwainUserInterfaceFlags.Show | TwainUserInterfaceFlags.Modal);
                }
                
    
  12. Build, and Run the program to test it.