指定的對象或值不存在

Question

我開發了一個UWP應用程序，從網絡攝像機捕獲視頻並保存到UWP的本地存儲，並且該應用程序在本地機器上完美地工作，但在RaspberryPi3上部署後，我得到fo

指定的對象或值不存在

文件被保存到應用的localData。調試後我知道錯誤是在以下幾行：

MediaEncodingProfile recordProfile = null; 
recordProfile = MediaEncodingProfile.CreateWmv(VideoEncodingQuality.Auto); 

await _mediaCapture.StartRecordToStorageFileAsync(recordProfile, recordStorageFile); 
_statuses.Add(DateTime.Now.ToString() + ": " + fileName + " Recording in progress"); 

任何幫助，將不勝感激。

Answer 1

The issue maybe due to your USB camera has no micro phone,  but the default capture mode is video and audio.

因此，呼籲MediaCapture.InitializeAsync（）之前，你需要這樣設置StreamingCaptureMode到視頻：

  var settings = new Windows.Media.Capture.MediaCaptureInitializationSettings(); 
      settings.StreamingCaptureMode = Windows.Media.Capture.StreamingCaptureMode.Audio; 
      await mediaCapture.InitializeAsync(settings);