Class ImageCaptureSource_CaptureAsync
    Public Shared Sub Test(outputFilename As String)
        Try
            Using image As Vintasoft.Imaging.VintasoftImage = CaptureImageFromCamera()
                image.Save(outputFilename)
            End Using
        Catch ex As System.Exception
            System.Console.WriteLine(ex.ToString())
        End Try
    End Sub

    Shared _captureCompletedEventArgs As Vintasoft.Imaging.Media.ImageCaptureCompletedEventArgs
    Shared _captureFaliedEventArgs As Vintasoft.Imaging.ExceptionEventArgs

    Private Shared Function CaptureImageFromCamera() As Vintasoft.Imaging.VintasoftImage
        _captureCompletedEventArgs = Nothing
        _captureFaliedEventArgs = Nothing

        ' get available capture devices
        Dim availableDevices As System.Collections.ObjectModel.ReadOnlyCollection(Of Vintasoft.Imaging.Media.ImageCaptureDevice) = Vintasoft.Imaging.Media.ImageCaptureDeviceConfiguration.GetCaptureDevices()
        If availableDevices.Count = 0 Then
            Throw New System.InvalidOperationException("No connected devices.")
        End If

        ' create capture source
        Dim captureSource As New Vintasoft.Imaging.Media.ImageCaptureSource()

        ' add handlers to CaptureCompleted and CaptureFailed events
        AddHandler captureSource.CaptureCompleted, New System.EventHandler(Of Vintasoft.Imaging.Media.ImageCaptureCompletedEventArgs)(AddressOf captureSource_CaptureCompleted)
        AddHandler captureSource.CaptureFailed, New System.EventHandler(Of Vintasoft.Imaging.ExceptionEventArgs)(AddressOf captureSource_CaptureFailed)

        ' set the first camera as capture device of capture source
        captureSource.CaptureDevice = availableDevices(0)

        ' start capturing
        captureSource.Start()

        ' initialite an asynchronous image capturing
        captureSource.CaptureAsync()

        ' wait while capturing request is finished
        While _captureCompletedEventArgs Is Nothing AndAlso _captureFaliedEventArgs Is Nothing
            System.Threading.Thread.Sleep(1)
        End While

        ' stop capturing
        captureSource.[Stop]()

        ' if capturing is failed
        If _captureFaliedEventArgs IsNot Nothing Then
            ' throws the exception
            Throw _captureFaliedEventArgs.Exception
        End If

        ' return captured image
        Return _captureCompletedEventArgs.GetCapturedImage()
    End Function

    Private Shared Sub captureSource_CaptureFailed(sender As Object, e As Vintasoft.Imaging.ExceptionEventArgs)
        _captureFaliedEventArgs = e
    End Sub

    Private Shared Sub captureSource_CaptureCompleted(sender As Object, e As Vintasoft.Imaging.Media.ImageCaptureCompletedEventArgs)
        _captureCompletedEventArgs = e
    End Sub

End Class

class ImageCaptureSource_CaptureAsync
{
    public static void Test(string outputFilename)
    {
        try
        {
            using (Vintasoft.Imaging.VintasoftImage image = CaptureImageFromCamera())
                image.Save(outputFilename);
        }
        catch (System.Exception ex)
        {
            System.Console.WriteLine(ex.ToString());
        }
    }

    static Vintasoft.Imaging.Media.ImageCaptureCompletedEventArgs _captureCompletedEventArgs;
    static Vintasoft.Imaging.ExceptionEventArgs _captureFaliedEventArgs;

    private static Vintasoft.Imaging.VintasoftImage CaptureImageFromCamera()
    {
        _captureCompletedEventArgs = null;
        _captureFaliedEventArgs = null;

        // get available capture devices
        System.Collections.ObjectModel.ReadOnlyCollection<Vintasoft.Imaging.Media.ImageCaptureDevice> availableDevices =
            Vintasoft.Imaging.Media.ImageCaptureDeviceConfiguration.GetCaptureDevices();
        if (availableDevices.Count == 0)
            throw new System.InvalidOperationException("No connected devices.");

        // create capture source
        Vintasoft.Imaging.Media.ImageCaptureSource captureSource = 
            new Vintasoft.Imaging.Media.ImageCaptureSource();

        // add handlers to CaptureCompleted and CaptureFailed events
        captureSource.CaptureCompleted += 
            new System.EventHandler<Vintasoft.Imaging.Media.ImageCaptureCompletedEventArgs>(captureSource_CaptureCompleted);
        captureSource.CaptureFailed += 
            new System.EventHandler<Vintasoft.Imaging.ExceptionEventArgs>(captureSource_CaptureFailed);
        
        // set the first camera as capture device of capture source
        captureSource.CaptureDevice = availableDevices[0];

        // start capturing
        captureSource.Start();

        // initialite an asynchronous image capturing
        captureSource.CaptureAsync();

        // wait while capturing request is finished
        while (_captureCompletedEventArgs == null && _captureFaliedEventArgs == null)
            System.Threading.Thread.Sleep(1);

        // stop capturing
        captureSource.Stop();

        // if capturing is failed
        if (_captureFaliedEventArgs != null)
            // throws the exception
            throw _captureFaliedEventArgs.Exception;

        // return captured image
        return _captureCompletedEventArgs.GetCapturedImage();
    }

    private static void captureSource_CaptureFailed(object sender, Vintasoft.Imaging.ExceptionEventArgs e)
    {
        _captureFaliedEventArgs = e;
    }

    private static void captureSource_CaptureCompleted(object sender, Vintasoft.Imaging.Media.ImageCaptureCompletedEventArgs e)
    {
        _captureCompletedEventArgs = e;
    }

}