C＃SiglanlR将数据保存在集线器中

Question

我有一些服务实现：

public class RemoteService : Hub
{
    public string GetImage()
    {
        SharpDX.Direct3D11.Device device;
        Output1 output1;
        int width, height;
        Texture2D screenTexture;
        InitDx(out device, out output1, out width, out height, out screenTexture);
        MemoryStream memoryStream = MakeScreenShot(device, output1, width, height, screenTexture);
        MemoryStream compressedMemoryStream = Compress(memoryStream);
        return JsonConvert.SerializeObject(compressedMemoryStream, Formatting.Indented, new MemoryStreamJsonConverter()); 
    }
    //...
}

在客户端上，我调用函数GetImage：

        myHub.Invoke<string>("GetImage").ContinueWith(task =>
        {
            if (task.IsFaulted)
            {
                Console.WriteLine("There was an error calling send: {0}",
                                  task.Exception.GetBaseException());
            }
            else
            {
                Console.WriteLine(task.Result);
            }
        });

我只想在服务端初始化InitDx(out device, out output1, out width, out height, out screenTexture);一次，而不是多次调用函数MakeScreenShot(device, output1, width, height, screenTexture);。

问题在于，SignalR为GetImage的每个请求创建RemoteService的新实例，而我将无法在RemoteService中保存初始化的变量。如何使用SignalR解决此问题。我在这个领域是新手，也许存在一些简单的常用方法。