GdPictureImaging.TwainBarCodeGetCount Method

If barcode detection is enabled, returns the number of bar codes found on the last acquired image.

public int TwainBarCodeGetCount();

Visual Basic

Public Function TwainBarCodeGetCount() As Integer

Returns

The number of bar codes found on the document image.

A value of 0 means the bar code engine was enabled but that no bar codes were found.

A value of -1 means the bar code engine was not enabled.

Remarks

Before using this function make sure that the barcode detection was enabled by the TwainSetBarcodeDetection() function.

Use the TwainBarCodeGetCount() function to determine how many barcodes have been detected on the last acquired image.

Example

Acquire single image and detect its barcodes

Copy Code

    Private Sub Command1_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command4.Click
        Dim ImageID As Integer
        Dim oGdPictureImaging As New GdPicture.GdPictureImaging
 
        oGdPictureImaging.SetLicenseNumber("XXX") 'Replace XXX by a valid demo or commercial license KEY
        If oGdPictureImaging.TwainOpenDefaultSource(Me.Handle) Then
            If oGdPictureImaging.TwainIsBarcodeDetectionAvailable Then
                oGdPictureImaging.TwainSetBarcodeDetection(True)
                ImageID = oGdPictureImaging.TwainAcquireToGdPictureImage(Me.Handle)
                If ImageID <> 0 Then
                    Dim BarCodeCount As Integer = oGdPictureImaging.TwainBarCodeGetCount
 
                    MsgBox(Str(BarCodeCount) + " barcode have been found in the scanned image")
 
                    For i As Integer = 1 To BarCodeCount
                        MsgBox("Type of barcode " + Str(i) + " is: " + oGdPictureImaging.TwainBarCodeGetType(i).ToString)
                        MsgBox("Value of barcode " + Str(i) + " is: " + oGdPictureImaging.TwainBarCodeGetValue(i))
                    Next
 
                    oGdPictureImaging.ReleaseGdPictureImage(ImageID)
                End If
            Else
                MsgBox("Error: Barcode detection is not available on this scanner")
            End If
 
            oGdPictureImaging.TwainCloseSource()
            MsgBox("Done !")
        Else
            MsgBox("can't open default source, twain state is: " & oGdPictureImaging.TwainGetState.ToString)
        End If
    End Sub