c# - R6025 纯虚函数调用

Question

我收到随机 R6025 - 将这个自定义 c# RTD 客户端用于 ThinkOrSwim 时随机出现纯虚函数调用错误。

我怎样才能a）调试它以找出问题所在，b）修复它？

当windows弹出消息框说有错误时，代码会一直在后台运行，不会抛出异常。但是当我在消息框上单击“确定”时，Windows 会关闭应用程序。

这是请求 RTD 数据的代码片段：

var tosClassId = new Guid(Registry.GetValue(@"HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Tos.RTD\CLSID", "", null).ToString());
var rtdClient = new RtdClient(tosClassId);

var date = DateTime.Now.Date;
foreach (var futureSymbol in futureSymbols) {
    var settlement = GetDouble(rtdClient, futureSymbol, "CLOSE");
    yield return new TOSEODDataPoint {
        Date = date,
        Settlement = settlement,
    };
}

static double GetDouble(IRtdClient client, string symbol, string topic) {
    object value;
    if (client.GetValue(TimeSpan.FromSeconds(3), out value, topic, symbol)) {
        try { return double.Parse(value.ToString()); } catch { return 0; }
    }
    return 0;
}

这是 RTD 客户端实现：

// Inspired by http://awkwardcoder.com/2014/01/24/excel-rtd-client-in-c/

public interface IRtdClient {
    bool GetValue(TimeSpan timeout, out object value, params object[] args);
}

public class RtdClient : IRtdClient {

    readonly Guid ServerId;
    static readonly Dictionary<Guid, IRtdServer> servers = new Dictionary<Guid, IRtdServer>();
    static readonly Dictionary<Guid, int> topicIds = new Dictionary<Guid, int>();

    public RtdClient(Guid serverId) {
        ServerId = serverId;
    }

    public bool GetValue(TimeSpan timeout, out object value, params object[] args) {

        value = null;
        var server = GetRtdServer();
        var topicId = GetTopicId();

        var sw = Stopwatch.StartNew();

        try {
            server.ConnectData(topicId, args, true);
            while (sw.Elapsed < timeout) {
                var alive = server.Heartbeat();
                if (alive != 1) {
                    // TODO: What should be done here?
                    return false;
                }
                var refresh = server.RefreshData(1);
                if (refresh.Length > 0) {
                    if (refresh[0, 0].ToString() == topicId.ToString()) {
                        value = refresh[1, 0];
                        return true;
                    }
                }
                Thread.Sleep(20);
            }
        } catch (Exception ex) {
            // TODO: Log exception
            return false;
        } finally {
            server.DisconnectData(topicId);
            sw.Stop();
        }
        return false;
    }

    IRtdServer GetRtdServer() {
        IRtdServer server;
        if (!servers.TryGetValue(ServerId, out server)) {
            Type rtd = Type.GetTypeFromCLSID(ServerId);
            server = (IRtdServer)Activator.CreateInstance(rtd);
            servers[ServerId] = server;
        }
        return server;
    }

    int GetTopicId() {
        int topicId = 0;
        if (topicIds.TryGetValue(ServerId, out topicId)) {
            topicId++;
        }
        topicIds[ServerId] = topicId;
        return topicId;
    }
}

[ComImport, TypeLibType((short)0x1040), Guid("EC0E6191-DB51-11D3-8F3E-00C04F3651B8")]
public interface IRtdServer {
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(10)]
    int ServerStart([In, MarshalAs(UnmanagedType.Interface)] IRTDUpdateEvent callback);

    [return: MarshalAs(UnmanagedType.Struct)]
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(11)]
    object ConnectData([In] int topicId, [In, MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_VARIANT)] ref object[] parameters, [In, Out] ref bool newValue);

    [return: MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_VARIANT)]
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(12)]
    object[,] RefreshData([In, Out] ref int topicCount);

    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(13)]
    void DisconnectData([In] int topicId);

    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(14)]
    int Heartbeat();

    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(15)]
    void ServerTerminate();
}

[ComImport, TypeLibType((short)0x1040), Guid("A43788C1-D91B-11D3-8F39-00C04F3651B8")]
public interface IRTDUpdateEvent {
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(10), PreserveSig]
    void UpdateNotify();

    [DispId(11)]
    int HeartbeatInterval {
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(11)]
        get;
        [param: In]
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(11)]
        set;
    }

    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), DispId(12)]
    void Disconnect();
}

Answer 1

以下是我如何通过减少失败次数来“解决”问题的方法……现在初始延迟为 200 毫秒，并且每次循环迭代时延迟加倍。（我仍在寻找真正的解决方案）

    public bool GetValue(TimeSpan timeout, out object value, params object[] args) {

        value = null;
        var server = GetRtdServer();
        var topicId = GetTopicId();

        var sw = Stopwatch.StartNew();
        var delay = 200;

        try {
            server.ConnectData(topicId, args, true);
            while (sw.Elapsed < timeout) {
                Thread.Sleep(delay);
                delay *= 2;
                var alive = server.Heartbeat();
                if (alive != 1) {
                    // TODO: What should be done here?
                    return false;
                }
                var refresh = server.RefreshData(1);
                if (refresh.Length > 0) {
                    if (refresh[0, 0].ToString() == topicId.ToString()) {
                        value = refresh[1, 0];
                        return true;
                    }
                }
            }
        } catch (Exception ex) {
            // TODO: Log exception
            return false;
        } finally {
            server.DisconnectData(topicId);
            sw.Stop();
        }
        return false;
    }