Public ReadOnly Default Property Item( _
   ByVal index As Integer _
) As AudioFormat

Dim instance As AudioFormats
Dim index As Integer
Dim value As AudioFormat
 
value = instance.Item(index)

public AudioFormat this( 
   int index
) {get;}

public:
property AudioFormat^ default [int] {
   AudioFormat^ get(int index);
}

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
      ' set an audio device first, you should use your audio device name here
      If capturectrl.AudioDevices("USB") Is Nothing Then
         Throw New Exception("No USB audio device available")
      End If

      capturectrl.AudioDevices("USB").Selected = True

      ' reference the audio formats object
      Dim audioformats As AudioFormats = capturectrl.AudioCaptureFormats

      ' check the index of 8hz, 16-bit, stereo
      Dim i As Integer = audioformats.IndexOf(8000, 16, 2)

      ' access the format via the collection indexer
      Dim af As AudioFormat = audioformats(i)

      ' check if the collection contains this format 
      ' (it should we just got it with IndexOf above)
      If audioformats.Contains(af) 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
   {
      // set an audio device first, you should use your audio device name here
      if (capturectrl.AudioDevices["USB"] == null)
         throw new Exception("No USB audio device available");

      capturectrl.AudioDevices["USB"].Selected = true;

      // reference the audio formats object
      AudioFormats audioformats = capturectrl.AudioCaptureFormats;

      // check the index of 8hz, 16-bit, stereo
      int i = audioformats.IndexOf(8000, 16, 2);

      // access the format via the collection indexer
      AudioFormat af = audioformats[i];

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