private void cbVideoSource_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e) { if (e == null) { return; } string val = e.AddedItems[0].ToString(); if (string.IsNullOrEmpty(val)) { return; } _videoCapture.Video_CaptureDevice_Name = val; _videoCapture.Video_CaptureDevice_ReadFormats(); // enumerate video formats cbVideoFormat.Items.Clear(); foreach (var format in _videoCapture.Video_CaptureDevice_Formats) { cbVideoFormat.Items.Add(format); } if (cbVideoFormat.Items.Count > 0) { cbVideoFormat.SelectedIndex = 0; } // enumerate video frame rates cbVideoFrameRate.Items.Clear(); foreach (var frameRate in _videoCapture.Video_CaptureDevice_FrameRates) { cbVideoFrameRate.Items.Add(frameRate); } if (cbVideoFrameRate.Items.Count > 0) { cbVideoFrameRate.SelectedIndex = 0; } }