c# - Windows Phone 8 中的视频文件到 Base64String 问题

Question

我在 Windows Phone 8 中创建了一个视频录制功能，并将字节数组转换为 base-64 字符串。我如何获得录音的持续时间？我的字节数组内存大小变得太大，因此 base64String 也太大，所以我收到这样的错误:

"System.OutOfMemoryException"

有关更多信息，请参阅下面的代码:

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);

对于视频长度:

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

Answer 1

每个应用程序都可以完成 memory limit .

尝试释放资源。对流使用 using 是一种很好的做法。是这样的: 私有(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);
}

关于视频时长，这里是thread on msdn forums