Public Function FindFastConfiguration( _
   ByVal workingFolder As String, _
   ByVal flags As TwainFastUserInterfaceFlags, _
   ByVal bitsPerPixel As Integer, _
   ByVal bufferIteration As Integer, _
   ByVal userConfigurations As RasterCollection(Of TwainFastConfiguration) _
) As TwainFindFastConfigurationResult

Dim instance As TwainSession
Dim workingFolder As String
Dim flags As TwainFastUserInterfaceFlags
Dim bitsPerPixel As Integer
Dim bufferIteration As Integer
Dim userConfigurations As RasterCollection(Of TwainFastConfiguration)
Dim value As TwainFindFastConfigurationResult
 
value = instance.FindFastConfiguration(workingFolder, flags, bitsPerPixel, bufferIteration, userConfigurations)

public TwainFindFastConfigurationResult FindFastConfiguration( 
   string workingFolder,
   TwainFastUserInterfaceFlags flags,
   int bitsPerPixel,
   int bufferIteration,
   RasterCollection<TwainFastConfiguration> userConfigurations
)

public:
TwainFindFastConfigurationResult FindFastConfiguration( 
   String^ workingFolder,
   TwainFastUserInterfaceFlags flags,
   int bitsPerPixel,
   int bufferIteration,
   RasterCollection<TwainFastConfiguration>^ userConfigurations
) 

Public Sub twain_FastConfiguration(ByVal sender As Object, ByVal e As TwainFastConfigurationEventArgs)
      ' ... set your code here
      e.Stop = False
   End Sub

   Public Sub FindFastConfigurationExample(ByVal parent As IWin32Window)
      Dim session As TwainSession = New TwainSession()
      session.Startup(parent, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None)

      session.EnableFastConfigurationEvent = True
      AddHandler session.FastConfiguration, AddressOf twain_FastConfiguration

      Dim twFastConfig As RasterCollection(Of TwainFastConfiguration) = Nothing
      Dim tempFastConfig As TwainFastConfiguration = New TwainFastConfiguration()
      tempFastConfig = TwainFastConfiguration.Default

      tempFastConfig.TransferMechanism = TwainTransferMode.File
      tempFastConfig.ImageFormat = Leadtools.RasterImageFormat.Bmp
      tempFastConfig.BitsPerPixel = 1
      twFastConfig.Add(tempFastConfig)

      tempFastConfig.TransferMechanism = TwainTransferMode.File
      tempFastConfig.ImageFormat = Leadtools.RasterImageFormat.Tif
      tempFastConfig.BitsPerPixel = 1
      twFastConfig.Add(tempFastConfig)

      Dim fastConfigRes As TwainFindFastConfigurationResult

      Try
         fastConfigRes = session.FindFastConfiguration(Path.Combine(LEAD_VARS.ImagesDir, ""), TwainFastUserInterfaceFlags.Show, 0, 1, twFastConfig)

         Dim msg As String
         MessageBox.Show("FindFastConfig method was successful")

         msg = String.Format("Result Scan Configs count = {0}", fastConfigRes.Tested.Count)
         MessageBox.Show(msg)

         msg = String.Format("Transfer Mode = {0}" & Constants.vbLf & "File Format = {1}" & Constants.vbLf & "Buffer Size = {2}" & Constants.vbLf & "Required Time = {3}" & Constants.vbLf, fastConfigRes.Tested(0).TransferMechanism, fastConfigRes.Tested(0).ImageFormat, fastConfigRes.Tested(0).BufferSize, fastConfigRes.Tested(0).RequiredTime)
         MessageBox.Show(msg, "Tested Scan Configurations...")

         msg = String.Format("Transfer Mode = {0}" & Constants.vbLf & "File Format = {1}" & Constants.vbLf & "Buffer Size = {2}" & Constants.vbLf & "Required Time = {3}" & Constants.vbLf, fastConfigRes.Best.TransferMechanism, fastConfigRes.Best.ImageFormat, fastConfigRes.Best.BufferSize, fastConfigRes.Best.RequiredTime)
         MessageBox.Show(msg, "Best Scan Configurations...")
      Catch ex As Exception
         MessageBox.Show(ex.Message)
      End Try

      session.Shutdown()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

public void twain_FastConfiguration(object sender, TwainFastConfigurationEventArgs e)
   {
      // ... set your code here
      e.Stop = false;
   }

   public void FindFastConfigurationExample(IWin32Window parent)
   {
      TwainSession session = new TwainSession();
      session.Startup(parent, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None);

      session.EnableFastConfigurationEvent = true;
      session.FastConfiguration += new EventHandler<TwainFastConfigurationEventArgs>(twain_FastConfiguration);

      RasterCollection<TwainFastConfiguration> twFastConfig = null;
      TwainFastConfiguration tempFastConfig = new TwainFastConfiguration();
      tempFastConfig = TwainFastConfiguration.Default;

      tempFastConfig.TransferMechanism = TwainTransferMode.File;
      tempFastConfig.ImageFormat = Leadtools.RasterImageFormat.Bmp;
      tempFastConfig.BitsPerPixel = 1;
      twFastConfig.Add(tempFastConfig);

      tempFastConfig.TransferMechanism = TwainTransferMode.File;
      tempFastConfig.ImageFormat = Leadtools.RasterImageFormat.Tif;
      tempFastConfig.BitsPerPixel = 1;
      twFastConfig.Add(tempFastConfig);

      TwainFindFastConfigurationResult fastConfigRes;

      try
      {
         fastConfigRes = session.FindFastConfiguration(Path.Combine(LEAD_VARS.ImagesDir, ""), TwainFastUserInterfaceFlags.Show, 0, 1, twFastConfig);

         string msg;
         MessageBox.Show("FindFastConfig method was successful");

         msg = String.Format("Result Scan Configs count = {0}", fastConfigRes.Tested.Count);
         MessageBox.Show(msg);

         msg = String.Format("Transfer Mode = {0}\nFile Format = {1}\nBuffer Size = {2}\nRequired Time = {3}\n",
            fastConfigRes.Tested[0].TransferMechanism,
            fastConfigRes.Tested[0].ImageFormat,
            fastConfigRes.Tested[0].BufferSize,
            fastConfigRes.Tested[0].RequiredTime);
         MessageBox.Show(msg, "Tested Scan Configurations...");

         msg = String.Format("Transfer Mode = {0}\nFile Format = {1}\nBuffer Size = {2}\nRequired Time = {3}\n",
            fastConfigRes.Best.TransferMechanism,
            fastConfigRes.Best.ImageFormat,
            fastConfigRes.Best.BufferSize,
            fastConfigRes.Best.RequiredTime);
         MessageBox.Show(msg, "Best Scan Configurations...");
      }
      catch (Exception ex)
      {
         MessageBox.Show(ex.Message);
      }

      session.Shutdown();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}