Selection Property (AudioFormats)

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public int Selection {get; set;}

'Declaration
 
Public Property Selection As Integer

'Usage
 
Dim instance As AudioFormats
Dim value As Integer
 
instance.Selection = value
 
value = instance.Selection

public int Selection {get; set;}

 get_Selection();
 set_Selection(value);

public:
property int Selection {
   int get();
   void set (    int value);
}

Property Value

The zero-based index of the selected item; otherwise -1 if no item is selected.

Assigning a value to this property can raise an error exception.

For more information, refer to the Error Codes.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Public _form As CaptureCtrlForm = New CaptureCtrlForm()
Public _result As Boolean = False
Public Sub AudioFormatExample()
  Try
     Dim count As Integer, freq As Integer = 0, bits As Integer = 0, channels As Integer = 0
     Dim found As Integer, selected As Integer = -1

     ' reference the capture control
     Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

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

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

     ' get count of available audio formats
     count = capturectrl.AudioCaptureFormats.Count

     ' reset the current selection to -1
     capturectrl.AudioCaptureFormats.Reset()

     ' reference the audioformats property
     Dim audioformats As AudioFormats = capturectrl.AudioCaptureFormats

     ' enumerate formats and select one
     For Each af As AudioFormat In audioformats
       freq = af.SampleFrequency
       bits = af.BitsPerSample
       channels = af.Channels

       ' select the format if it matches some criteria
       If freq = 8000 AndAlso bits = 16 AndAlso channels = 2 Then
         af.Selected = True
         Exit For
       End If
     Next af

     ' get the currently selected format
     selected = audioformats.Selection

     ' find a format based on frequency, bits/channel and number of channels
     found = audioformats.IndexOf(8000, 8, 2)

     ' our found format is not selected, so select it
     If found <> selected Then
       audioformats.Selection = found
     End If

     ' get the new selected format
     selected = audioformats.Selection

     ' set our result based on what we expect
     _result = (count > 0 AndAlso selected = found)
  Catch e1 As Exception
     _result = False
  End Try
End Sub

public CaptureCtrlForm _form = new CaptureCtrlForm();
public bool _result = false;
public void AudioFormatExample()
{
   try
   {
      int count, freq = 0, bits = 0, channels = 0;
      int found, selected = -1;

      // reference the capture control
      CaptureCtrl capturectrl = _form.CaptureCtrl;

      // set an audio device, use the name of your device here
      if (capturectrl.AudioDevices["USB"] == null)
         throw new Exception("No USB audio device available");

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

      // get a count of the available audio formats
      count = capturectrl.AudioCaptureFormats.Count;

      // reset the current selection to -1
      capturectrl.AudioCaptureFormats.Reset();

      // reference the audioformats property
      AudioFormats audioformats = capturectrl.AudioCaptureFormats;

      // enumerate formats and select one
      foreach (AudioFormat af in audioformats)
      {
         freq = af.SampleFrequency;
         bits = af.BitsPerSample;
         channels = af.Channels;

         // select the format if it matches some criteria
         if (freq == 8000 && bits == 16 && channels == 2)
         {
            af.Selected = true;
            break;
         }
      }

      // get the currently selected format
      selected = audioformats.Selection;

      // find a format based on frequency, bits/channel and number of channels
      found = audioformats.IndexOf(8000, 8, 2);

      // the format found format is not selected, so select it
      if (found != selected)
         audioformats.Selection = found;

      // get the new selected format
      selected = audioformats.Selection;

      // set our result based on what we expect
      _result = (count > 0 && selected == found);
   }
   catch (Exception)
   {
      _result = false;
   }
}

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

AudioFormats Class
AudioFormats Members