在Windows Phone 8中將視頻文件轉換爲Base64String問題

Question

我在Windows Phone 8中創建了一個視頻錄製功能，並將字節數組轉換爲base-64字符串。我如何獲得錄音的持續時間？我的字節數組的內存大小變得過大，因此base64String也太大了，所以我得到的錯誤是這樣的：

"System.OutOfMemoryException" 

更多信息，請參閱我下面的代碼：

private IsolatedStorageFileStream isoVideoFile; 
string isoVideoFileName = "CameraMovie.mp4"; 

isoVideoFile = new IsolatedStorageFileStream(isoVideoFileName, 
        FileMode.OpenOrCreate, FileAccess.ReadWrite, 
        IsolatedStorageFile.GetUserStoreForApplication()); 
MemoryStream stream = new MemoryStream(); 
isoVideoFile.Write(stream.GetBuffer(), 0, (int)stream.Position); 

byte[] binaryData = new Byte[isoVideoFile.Length]; 
long bytesRead = isoVideoFile.Read(binaryData, 0, (int)isoVideoFile.Length); 
string videofile = Convert.ToBase64String(binaryData, 0, binaryData.Length); 

對於視頻長度：

private void Element_MediaOpened1(object sender, RoutedEventArgs e) 
    { 
     if (mediaElement_1.NaturalDuration.HasTimeSpan) 
     timelineSlider.Maximum = mediaElement_1.NaturalDuration.TimeSpan.TotalSeconds; 
    } 

Answer 1

您已經完成每個應用程序memory limit。

嘗試處置資源。在流中使用using是個好習慣。類似這樣的： private IsolatedStorageFileStream isoVideoFile; string isoVideoFileName =「CameraMovie.mp4」;

using(isoVideoFile = new IsolatedStorageFileStream(isoVideoFileName, 
        FileMode.OpenOrCreate, FileAccess.ReadWrite, 
        IsolatedStorageFile.GetUserStoreForApplication())) 
{ 
    using(MemoryStream stream = new MemoryStream()) 
    { 
     isoVideoFile.Write(stream.GetBuffer(), 0, (int)stream.Position); 
    } 
    byte[] binaryData = new Byte[isoVideoFile.Length]; 
    long bytesRead = isoVideoFile.Read(binaryData, 0, (int)isoVideoFile.Length); 
    string videofile = Convert.ToBase64String(binaryData, 0, binaryData.Length); 
} 

又是怎麼回事視頻時長，這裏是thread on msdn forums