Get Twain Capability

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

Start Visual Studio.
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 "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:

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, "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

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 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

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:

                  
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

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:

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

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:

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

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:

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

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); 
   } 
}