Twain Feeder Tutorial # 2

Take the following steps to start a project:

Start Visual Studio .NET.
Choose File->New->Project… from the menu.
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.
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.
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 a 1 instance of Button control to the top of the form and set the following properties for them:

Text	Name
Acquire	buttonAcquire

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:

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

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

Declare the following private variable:

Private WithEvents twnSession As TwainSession

private TwainSession twnSession;

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

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. 
      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.None) 
   Catch ex As Exception 
      MessageBox.Show(ex.Message) 
   End Try 
End Sub

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. 
      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.None); 
   } 
   catch (Exception ex) 
   { 
      MessageBox.Show(this, ex.Message); 
   } 
}

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

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

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 buttonAcquire Click event and code it as follows:

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

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); 
}