Событие Newframe не отображается в списке событий videosource?

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Imports AForge.Video
Imports AForge.Video.DirectShow
Imports AForge.Controls
Public Class Imagecapture
    Private videodevices As FilterInfoCollection
    Private videosource As VideoCaptureDevice
    Private Sub PictureBox1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PictureBox1.Click

    End Sub

    Private Sub Imagecapture_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        videodevices = New FilterInfoCollection(FilterCategory.VideoInputDevice)

        For Each device As FilterInfo In videodevices
            ComboBox1.Items.Add(device.Name)
        Next
        videosource = New VideoCaptureDevice()
    End Sub

    Private Sub btnstartstop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnstartstop.Click
        If (videosource.IsRunning) Then
            videosource.Stop()
            PictureBox1.Image = Nothing
            PictureBox1.Invalidate()
        Else

            videosource = New VideoCaptureDevice(videodevices(ComboBox1.SelectedIndex).MonikerString)
            'set new frame event handler
            videosource.NewFrame += New NewFrameEventArgs(videosource_newframe)

        End If

    End Sub
    Sub videosource_newframe(ByVal sender As Object, ByVal eventArgs As NewFrameEventArgs)

    End Sub
End Class

Что я уже пробовал:

видеоисточник.Вызов newframe += новый NewFrameEventArgs(videosource_newframe)

В этом событии NewFrame всегда отображается ошибка

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