How to retrieve images from scanner or camera (TWAIN or WIA compatible) with Bytescout Scan SDK for .NET in Visual Basic.NET (VB.NET) - ByteScout

How to retrieve images from scanner or camera (TWAIN or WIA compatible) with Bytescout Scan SDK for .NET in Visual Basic.NET (VB.NET)

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This sample code demonstrates how to transfer images from scanner or web-camera TWAIN and WIA devices with Bytescout Scan SDK for .NET. Full sample code is included into the SDK.


Screenshot of VB.NET test application:
screenshot of Visual Basic .NET test application  with Scan SDK

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.Data

Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Imports System.Drawing.Imaging

Imports Bytescout.Scan
Imports System.IO


Public Class Form1

    ' Starts Asynchronous scan into images. When scan is finished then scan_TransferFinished event is called and array with images objects is passed into this event
    Private Sub btnScanToImagesAsync_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnScanToImagesAsync.Click
        ' create new Scan object

        Dim scan As New Scan()

        ' set Scan object to save images into images array (will be passed as a paramtere in scan_TransferFinished event
        scan.SaveTo = SaveTo.ImageObject
        AddHandler scan.TransferFinished, AddressOf scan_TransferFinished

        ' set function for scan finished event to indicate when image transfer is finished

        ' see scan_TransferFinished event below
        ' acquire images
        scan.AcquireImagesAsync(Me.Handle)
    End Sub

    ' this event captures scanned images and fills images into tabs

    ' you can also iterate through scannedImages array to get each image as an Image object instead
    Private Sub scan_TransferFinished(ByVal sender As Scan, ByVal scannedImages As ArrayList)
        FillTabsWithImages(scannedImages)
    End Sub

    ' this function puts retrieved images objects into tabs on the form
    Private Sub FillTabsWithImages(ByVal images As ArrayList)
        tabControl1.TabPages.Clear()
        For i As Integer = 0 To images.Count - 1

            Dim page As New TabPage()

            Dim pb As New PictureBox()
            pb.Dock = DockStyle.Fill
            pb.SizeMode = PictureBoxSizeMode.Zoom

            If TypeOf images(i) Is Image Then

                page.Text = "Image " + (i + 1).ToString()
                pb.Image = DirectCast(images(i), Image)
            Else
                page.Text = DirectCast(images(i), String)
                pb.Image = Image.FromFile(DirectCast(images(i), String))
            End If

            page.Controls.Add(pb)

            tabControl1.TabPages.Add(page)
        Next
    End Sub

    ' acquire images into files automatically saved into the given folder with given image format and filename
    Private Sub btnScanToFilesAsync_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnScanToFilesAsync.Click
        ' create new Scan object

        Dim scan As New Scan()

        ' set SDK to save images into files
        scan.SaveTo = SaveTo.File
        ' scan.FileNamingTemplate = "ScannedImage_{0:D2}"; // you can set output filename template
        ' set output format as JPG image format

        scan.OutputFormat = OutputFormat.JPEG
        AddHandler scan.TransferFinished, AddressOf scan_TransferFinished

        ' you can set output folder as well, by default output folder is the same where executable .exe is running            
        'scan.OutputFolder = Path.GetTempPath();


        ' assign the event to indicate when image transfer is finished

        ' acquire images
        scan.AcquireImagesAsync(Me.Handle)
    End Sub

    ' displays ready-to-use options dialog for the scan SDK
    Private Sub btnOptions_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOptions.Click
        Scan.ShowOptionsDialog(New Scan())
    End Sub

End Class
	
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