Public _result As Boolean = False
Public _form As CaptureCtrlForm = New CaptureCtrlForm()
Public Sub IndexContainsExample()
   ' reference the capture control
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

   Try
      ' select a video device, use your device name here instead of Analog
      If capturectrl.VideoDevices("Analog") Is Nothing Then
         Throw New Exception("No Analog video tuner device available")
      End If

      capturectrl.VideoDevices("Analog").Selected = True

      ' reference the video devices object
      Dim devices As Devices = capturectrl.VideoDevices

      ' check the index of a USB video device
      Dim i As Integer = devices.IndexOf("USB")

      Dim dev As Device = Nothing
      If i > -1 Then
         ' access the input via the collection indexer
         dev = devices(i)
      End If

      ' check if the collection contains this input 
      ' (it should we just got it with IndexOf above)
      If devices.Contains(dev) Then
         ' set the result to what we expect
         _result = True
      End If
   Catch e1 As Exception
      _result = False
   End Try
End Sub

public bool _result = false;
public CaptureCtrlForm _form = new CaptureCtrlForm();
public void IndexContainsExample()
{
   // reference the capture control
   CaptureCtrl capturectrl = _form.CaptureCtrl;

   try
   {
      // select a video device, use your device name here instead of Analog
      if (capturectrl.VideoDevices["Analog"] == null)
         throw new Exception("No Analog video tuner device available");

      capturectrl.VideoDevices["Analog"].Selected = true;

      // reference the video devices object
      Devices devices = capturectrl.VideoDevices;

      // check the index of a USB video device
      int i = devices.IndexOf("USB");

      Device dev = null;
      if (i > -1)
         // access the input via the collection indexer
         dev = devices[i];

      // check if the collection contains this input 
      // (it should we just got it with IndexOf above)
      if (devices.Contains(dev))
      {
         // set the result to what we expect
         _result = true;
      }
   }
   catch (Exception)
   {
      _result = false;
   }
}