Selection Property (AudioFormats)

Visual Basic
C#
C++/CLI

'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;}

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

Imports Leadtools
Imports Leadtools.MediaFoundation
Imports LeadtoolsMediaFoundationExamples.Fixtures

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

using Leadtools;
using Leadtools.MediaFoundation;
using LeadtoolsMediaFoundationExamples.Fixtures;

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 count of 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);

      // our 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

Reference

AudioFormats Class
AudioFormats Members