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 "Visual Basic 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:

[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
               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.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.SetLicense(RasterSupportType.Document, "TestKey");
                  twnSession = new TwainSession();
                  twnSession.Startup(this, "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:

[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);
               }
            }

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);
            }

Build, and Run the program to test it.