ASP.NET MVC 管理对象

Question

NET MVC，现在我有一种情况，在我的控制器中，当单击按钮时，我正在创建一个局部视图，并且视图的模型包含一个侦听事件的类。

StreamModel streamModel = m_StreamModel = new StreamModel(cameraId, rgsLiveVideoWebCall);

string view = RenderRazorViewToString("ImageView", streamModel);

public string RenderRazorViewToString(string viewName, object model)
    {
        ViewData.Model = model;
        using (var sw = new StringWriter())
        {
            var viewResult = ViewEngines.Engines.FindPartialView(ControllerContext,
                                                                     viewName);
            var viewContext = new ViewContext(ControllerContext, viewResult.View,
                                         ViewData, TempData, sw);
            viewResult.View.Render(viewContext, sw);
            viewResult.ViewEngine.ReleaseView(ControllerContext, viewResult.View);
            return sw.GetStringBuilder().ToString();
        }
    }

StreamModel 类如下所示：

public class StreamModel
{
    public StreamHolder StreamHolder { get; set; }

    public string Image { get; set; }

    public StreamModel(string cameraId, string url)
    {
        StreamHolder = new StreamHolder(cameraId, url);
    }
}

还有这样的 StreamHolder 持有者类：

public class StreamHolder
{
    private object GetNewImageLock = new object();

    public string CameraId { get; set; }

    private MJPEGStream m_MJPEGStream;

    public byte[] CurrentImageBytes { get; set; }

    public string ImageBase64 { get; set; }


    public StreamHolder(string cameraId, string url)
    {
        CameraId = cameraId;
        CurrentImageBytes = null;
        ImageBase64 = null;
        lock (this)
        {
            m_MJPEGStream = new MJPEGStream(url);
            m_MJPEGStream.RequestTimeout = 100000;
            m_MJPEGStream.ForceBasicAuthentication = true;
            m_MJPEGStream.Login = "admin";
            m_MJPEGStream.Password = "admin";
            m_MJPEGStream.NewFrame += stream_NewFrame;
            m_MJPEGStream.PlayingFinished += stream_PlayingFinished;
            m_MJPEGStream.VideoSourceError += stream_VideoSourceError;
            m_MJPEGStream.Start();
        }
    }

    public void StopStreaming()
    {
        lock (this)
        {
            if (m_MJPEGStream != null)
            {
                try
                {
                    m_MJPEGStream.Stop();
                    m_MJPEGStream.WaitForStop();
                    m_MJPEGStream.NewFrame -= stream_NewFrame;
                    m_MJPEGStream.PlayingFinished -= stream_PlayingFinished;
                    m_MJPEGStream.VideoSourceError -= stream_VideoSourceError;
                    m_MJPEGStream = null;
                }
                catch { }
            }
        }
    }

    private void stream_VideoSourceError(object sender, VideoSourceErrorEventArgs eventArgs)
    {
        StopStreaming();
    }

    private void stream_PlayingFinished(object sender, ReasonToFinishPlaying reason)
    {
        StopStreaming();
    }

    private void stream_NewFrame(object sender, NewFrameEventArgs eventArgs)
    {
        lock (GetNewImageLock)
        {
            if (HomeController.m_LastImageRequest != null && (DateTime.Now - HomeController.m_LastImageRequest).TotalSeconds > 10)
            {
                StopStreaming();
                return;
            }

            if (eventArgs.Frame != null)
            {
                CurrentImageBytes = BitmapToBytes(eventArgs.Frame);
                var base64 = Convert.ToBase64String(CurrentImageBytes);
                ImageBase64 = String.Format("data:image/gif;base64,{0}", base64);
            }
        }
    }

    // This method is for converting bitmap into a byte array
    private static byte[] BitmapToBytes(Bitmap img)
    {
        byte[] byteArray = new byte[0];
        using (MemoryStream stream = new MemoryStream())
        {
            img.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
            stream.Close();
            byteArray = stream.ToArray();
        }
        return byteArray;
    }
}

我有两个主要问题： 1) 我可能有超过 1 个此模型的实例，我需要在创建它们后访问和管理它们。 2）当标签/窗口关闭时，我需要正确处理它们。

Answer 1

你可以拥有一个

private static List<StreamModel> streamModels = new List<StreamModel>();

在你的一门课上。你可以定义一个方法，像这样：

public static StreamModel generateStreamModel(string cameraid, string url) {
    StreamModel streamModel = new StreamModel(cameraid, url);
    streamModels.Add(streamModel);
    return streamModel;
}

要释放实例，请将其从 streamModels 中删除。如果未引用，则应由垃圾收集器收集。