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Get Twain Capability
Take the following steps to start a project and to add some code to get a Twain Capability:
  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 "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 .
  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 15\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 4 instance of Button control to the top of the form and set the following properties for them:
    TextName
    Select SourcebuttonSelectSource
    Use CapabilitybuttonUseCapability
    Set BrightnessbuttonSetBrightness
    AcquirebuttonAcquire
  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, "LEAD Technologies, Inc.", "LEAD TWAIN .NET", "Version 15", "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.
          RasterSupport.Unlock(RasterSupportType.Document, "TestKey");
    
          twnSession = new TwainSession();
          twnSession.Startup(this, "LEAD Technologies, Inc.", "LEAD Twain .NET", "Version 14", "LEADTools Twain test sample", 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 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);
       }
    }
    
  11. 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);
       }
    }
    
  12. 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);
       }
    }
    
  13. 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);
       }
    }
    
  14. 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:\Program Files\LEAD Technologies\LEADTOOLS 15\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:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Twain.bmp";
          twnPros.DataTransfer = dataTransfer;
          twnSession.Properties = twnPros;
          twnSession.Acquire(TwainUserInterfaceFlags.Show);
       }
       catch (Exception ex)
       {
          MessageBox.Show(ex.Message);
       }
    }
    
  15. Build, and Run the program to test it.