Get Twain Capability

Take the following steps to start a project and to add some code to get a Twain Capability:

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 "GetTwainCapability" 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 4 instances of Button control to the top of the form and set the following properties for them:

Text	Name
Select Source	buttonSelectSource
Use Capability	buttonUseCapability
Set Brightness	buttonSetBrightness
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.
                  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, "LEAD Technologies, Inc.", "LEAD TWAIN .NET", "Version 16", "LEADTOOLS TWAIN test sample", 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.
                  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:

[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 buttonSelectSource Click event and code it as follows:

[Visual Basic]


             
            Private Sub buttonSelectSource_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonSelectSource.Click
               Try
                  twnSession.SelectSource(String.Empty)
               Catch ex As Exception
                  MessageBox.Show(ex.Message)
               End Try
            End Sub

[C#]


            private void buttonSelectSource_Click(object sender, System.EventArgs e)
            {
               try
               {
                  twnSession.SelectSource(string.Empty);
               }
               catch (Exception ex)
               {
                  MessageBox.Show(this, ex.Message);
               }
            }

Add an event handler to the buttonUseCapability Click event and code it as follows:

[Visual Basic]


            Private Sub buttonUseCapability_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonUseCapability.Click
               Try
                  Dim twGetCapability As TwainCapability = twnSession.GetCapability(TwainCapabilityType.ImageTransferMechanism, TwainGetCapabilityMode.GetCurrent)
                  
                  If twGetCapability.Information.ContainerType = TwainContainerType.OneValue Then
                     Dim capValue As TwainCapabilityValue = twGetCapability.OneValueCapability.Value
                     
                     If capValue <> TwainCapabilityValue.TransferMechanismFile Then
                        Dim twSetCapability As TwainCapability
                        
                        twSetCapability = new TwainCapability
                        twSetCapability.Information.ContainerType = TwainContainerType.OneValue
                        twSetCapability.Information.Type = TwainCapabilityType.ImageTransferMechanism
                        
                        twSetCapability.OneValueCapability.ItemType = TwainItemType.Uint16
                        twSetCapability.OneValueCapability.Value = TwainCapabilityValue.TransferMechanismFile
                        
                        twnSession.SetCapability(twSetCapability, TwainSetCapabilityMode.Set)
                     End If
                  End If
               Catch ex As Exception
                  MessageBox.Show(ex.Message)
               End Try
            End Sub

[C#]


            private void buttonUseCapability_Click(object sender, System.EventArgs e)
            {
               try
               {
                  TwainCapability twGetCapability = twnSession.GetCapability(TwainCapabilityType.ImageTransferMechanism, TwainGetCapabilityMode.GetCurrent);
                  
                  if (twGetCapability.Information.ContainerType == TwainContainerType.OneValue)
                  {
                     TwainCapabilityValue capValue = (TwainCapabilityValue)twGetCapability.OneValueCapability.Value;
                     
                     if (capValue != TwainCapabilityValue.TransferMechanismFile)
                     {
                        TwainCapability twSetCapability;
                        
                        twSetCapability = new TwainCapability();
                        twSetCapability.Information.ContainerType = TwainContainerType.OneValue;
                        twSetCapability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
                        
                        twSetCapability.OneValueCapability.ItemType = TwainItemType.Uint16;
                        twSetCapability.OneValueCapability.Value = TwainCapabilityValue.TransferMechanismFile;
                        
                        twnSession.SetCapability(twSetCapability, TwainSetCapabilityMode.Set);
                     }
                  }
               }
               catch (Exception ex)
               {
                  MessageBox.Show(this, ex.Message);
               }
            }

Add an event handler to the buttonSetBrightness Click event and code it as follows:

[Visual Basic]


            Private Sub buttonSetBrightness_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonSetBrightness.Click
               Try
                  Dim twCapability As TwainCapability = new TwainCapability
                  
                  twCapability.Information.ContainerType = TwainContainerType.OneValue
                  twCapability.Information.Type = TwainCapabilityType.ImageBrightness
                  
                  Dim brightnessValue As Integer = 50
                  twCapability.OneValueCapability.ItemType = TwainItemType.Fix32
                  twCapability.OneValueCapability.Value = brightnessValue
                  
                  twnSession.SetCapability(twCapability, TwainSetCapabilityMode.Set)
               Catch ex As Exception
                  MessageBox.Show(ex.Message)
               End Try
            End Sub

[C#]


            private void buttonSetBrightness_Click(object sender, System.EventArgs e)
            {
               try
               {
                  TwainCapability twCapability = new TwainCapability();
                  
                  twCapability.Information.ContainerType = TwainContainerType.OneValue;
                  twCapability.Information.Type = TwainCapabilityType.ImageBrightness;
                  
                  float brightnessValue = 50;
                  twCapability.OneValueCapability.ItemType = TwainItemType.Fix32;
                  twCapability.OneValueCapability.Value = brightnessValue;
                  
                  twnSession.SetCapability(twCapability, TwainSetCapabilityMode.Set);
               }
               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
               Try
                  Dim twnPros As TwainProperties = twnSession.Properties
                  Dim dataTransfer As TwainDataTransferProperties = twnPros.DataTransfer
                  dataTransfer.FileName = "C:\Users\Public\Documents\LEADTOOLS Images\Twain.bmp"
                  twnPros.DataTransfer = dataTransfer
                  twnSession.Properties = twnPros
                  twnSession.Acquire(TwainUserInterfaceFlags.Show)
               Catch ex As Exception
                  MessageBox.Show(ex.Message)
               End Try
            End Sub

[C#]


            private void buttonAcquire_Click(object sender, System.EventArgs e)
            {
               try
               {
                  TwainProperties twnPros = twnSession.Properties;
                  TwainDataTransferProperties dataTransfer = twnPros.DataTransfer;
                  dataTransfer.FileName = @"C:\Users\Public\Documents\LEADTOOLS Images\Twain.bmp";
                  twnPros.DataTransfer = dataTransfer;
                  twnSession.Properties = twnPros;
                  twnSession.Acquire(TwainUserInterfaceFlags.Show);
               }
               catch (Exception ex)
               {
                  MessageBox.Show(ex.Message);
               }
            }

Build, and Run the program to test it.