Available in the LEADTOOLS Imaging toolkit. |
Using the Fast TWAIN Feature (Visual Basic)
Take the following steps to start a project and to add some code that acquires the images using Fast Twain:
1. |
Start Visual Basic. |
2. |
Add the LEAD RasterTwain Object Library and LEAD Raster Variant Object Library to your project. |
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On the Project pull-down menu, use the References option, and select the LEAD RasterTwain Object Library. |
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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
optMemory.Value = True
6. |
Add the following code to the main form's Unload procedure: |
RasterTwain.EndSession
7. |
At the top of your main form, add 1 check box |
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Name |
Caption |
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chkUseBufferSize |
Use Buffer Size |
8. |
Add the following radio buttons: |
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Name |
Caption |
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optNative |
Native Mode |
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optMemory |
Memory Mode |
9. |
Add the following button: |
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Name |
Caption |
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cmdAcquire |
Fast Acquire |
10. |
Add the two text boxes and name them as follows: |
txtBufferSize
txtFName
11. |
Code the Fast Acquire control's Click procedure as follows. In online help, you can use the Edit pull-down menu to copy the block of code. |
If optMemory.Value = True Then
RasterTwain.FastTransferMode = L_LTWAIN_BUFFER_MODE
RasterTwain.FastFormat = FILE_CCITT_GROUP4
Else
RasterTwain.FastTransferMode = L_LTWAIN_NATIVE_MODE
RasterTwain.FastFormat = FILE_TIF
End If
RasterTwain.FastBitsPerPixel = 1
RasterTwain.FastUsePreferredBufferSize = chkUseBufferSize.Value
RasterTwain.FastBufferSize = Val(txtBufferSize.Text)
nRet = RasterTwain.AcquireMulti(txtFName.Text, L_LTWAIN_SHOW_USER_INTERFACE Or L_LTWAIN_USE_THREAD_MODE, True)
If nRet = 0 Then
MsgBox "Fast Scanning process completed successfully..."
Else
MsgBox "The AcquireMulti method failed, Error = " + Str(nRet)
End If
12. |
Save your project and run your program to test it. |