''' <summary>
''' Starts the asynchronous image acquisition from scanner.
''' </summary>
Private Sub StartScan(ByVal deviceManager As Vintasoft.Twain.DeviceManager)
    ' specify TWAIN name of this application
    deviceManager.ApplicationProductName = "MyTwainApplication"
    Try
        ' open the device manager
        deviceManager.Open()

        ' show the default device selection dialog
        If Not deviceManager.ShowDefaultDeviceSelectionDialog() Then
            ' exit if default device is not selected
            Return
        End If

        ' get reference to the default device
        Dim device As Vintasoft.Twain.Device = deviceManager.DefaultDevice
        ' acquire image(s) from the device
        device.Acquire()
    Catch ex As Vintasoft.Twain.TwainException
        Console.WriteLine(ex.Message)
    End Try
End Sub

/// <summary>
/// Starts the asynchronous image acquisition from scanner.
/// </summary>
void StartScan(Vintasoft.Twain.DeviceManager deviceManager)
{
    // specify TWAIN name of this application
    deviceManager.ApplicationProductName = "MyTwainApplication";
    try
    {
        // open the device manager
        deviceManager.Open();

        // show the default device selection dialog
        if (!deviceManager.ShowDefaultDeviceSelectionDialog())
            // exit if default device is not selected
            return;

        // get reference to the default device
        Vintasoft.Twain.Device device = deviceManager.DefaultDevice;
        // acquire image(s) from the device
        device.Acquire();
    }
    catch (Vintasoft.Twain.TwainException ex)
    {
        System.Console.WriteLine(ex.Message);
    }
}