Get a Fast Twain Scan from a Scanner (Visual Basic)

Take the following steps to start a project and to add some code to find the fastest configuration for your scanner using the LEADTOOLS Fast TWAIN feature:

1.	Start Visual Basic.
2.	Add the LEAD RasterTwain Object Library and LEAD Raster Variant Object Library to your project.
	On the Project pull-down menu, use the References option, and select the LEAD RasterTwain Object Library.
	On the Project pull-down menu, use the References option, and select the LEAD Raster Variant Object Library.
3.	Add the LEAD Main Control to your project. On the Project pull-down menu, use the Components option, and select the LEAD Main ActiveX Control.
4.	Add the following code to the general declarations section of your project:

Public TwainCap As New LEADTwainCapability_U
Public WithEvents RasterTwain As LEADRasterTwain_U
Public nXferMode As Integer
Public nRet As Integer

5.	Add the following code to the main form's Load procedure:

Set RasterTwain = New LEADRasterTwain_U
RasterTwain.InitSession hWnd
RasterTwain.EnableMethodErrors = False

' Unlock Document support.
' Note that this is a sample key, which will not work in your toolkit.
RasterTwain.UnlockSupport L_SUPPORT_DOCUMENT, "TestKey"

6.	Add the following code to the main form's Unload procedure:

RasterTwain.EndSession
Set RasterTwain = Nothing

7.	At the top of your main form, add 3 command buttons as following:
	Name	Caption
	cmdSelectSource	Select Source
	cmdFindFastConfig	Find Fast Config
	cmdAcquireFastConfig	Acquire Fast Config
8.	Code the "Select Source" control's Click procedure as follows. In online help, you can use the Edit pull-down menu to copy the block of code.

Private Sub cmdSelectSource_Click()
RasterTwain.SelectSource
End Sub

9.	Code the "Find Fast Config" control's Click procedure as follows. In online help, you can use the Edit pull-down menu to copy the block of code.

Private Sub cmdFindFastConfig_Click()
   RasterTwain.UserFastConfigsCount = 0
   RasterTwain.EnableFastConfigEvent = False
   nRet = RasterTwain.FindFastConfig ("c:\temp", L_LTWAIN_SHOW_USER_INTERFACE Or L_LTWAIN_USE_THREAD_MODE, 8, 5)

   If nRet = 0 Then
      MsgBox "Find Fast Configuration process completed."
   Else
      MsgBox "An error occurred during the Finding Fast Configuration process."
   End If
End Sub

10.	Code the "Acquire Fast Config" control's Click procedure as follows. In online help, you can use the Edit pull-down menu to copy the block of code.

Private Sub cmdAcquireFastConfig_Click()
   RasterTwain.FastTransferMode = RasterTwain.BestFastConfig.TransferMode
   RasterTwain.FastFormat = RasterTwain.BestFastConfig.FileFormat
   RasterTwain.FastBitsPerPixel = RasterTwain.BestFastConfig.BitsPerPixel
   RasterTwain.FastBufferSize = RasterTwain.BestFastConfig.BufferSize

   RasterTwain.FastUsePreferredBufferSize = True
   RasterTwain.EnableAcquireMultiEvent = False

   nRet = RasterTwain.AcquireMulti ("c:\temp\test", L_LTWAIN_SHOW_USER_INTERFACE, True)

   If nRet = 0 Then
      MsgBox "Image acquisition using the Fast TWAIN Configuration is completed."
   Else
      MsgBox "An error occurred while acquiring images using the Fast TWAIN Configuration."
   End If
End Sub

11.	Save your project and run your program to test it.