Question

我对ManualResetEvent对象中的方法Set（）有一个奇怪的问题。我创建了一个嵌入DLL COM对象的库，用于与机器通信。

在向COM对象（m_server对象）发送消息之前，我订阅了CommandReceived事件，然后发送消息（SendMessage方法），我等待来自COM对象的响应（WaitOne）。

引发事件后，我使用Set（）方法通知ManualResetEvent。有时候，我得到一个例外“Handle is Invalid。”。

显然，ManualResetEvent使用内部句柄。由于某种原因，它会被系统无效。

这是代码：

using (ManualResetEvent msgResponseWait = new ManualResetEvent(false)) {

__RCServer_CommandReceivedEventHandler onCommandReceivedDlg = delegate(ref short isock, string sCommand) {
    try {
        if (MessageReceived != null) {
            MessageReceived(this, null);
        }
        ServerMessage receivedServerMessage = ServerMessage.Parse(sCommand);
        if (msg.Command == receivedServerMessage.Command && msg.GvLocation == receivedServerMessage.GvLocation) {
            msg.Value = receivedServerMessage.Value;
            msg.ReceivedResponseDateTime = DateTime.Now;
            msgResponseWait.Set();
        } else {
            m_logger.AddTrace(
                string.Format("Mismatch between request/response." + Environment.NewLine +
                                "Command sent: '{0}' / Command received: '{1}'" + Environment.NewLine +
                                "Location sent: '{2}' / Location received: '{3}'",
                                msg.Command, receivedServerMessage.Command,
                                msg.GvLocation, receivedServerMessage.GvLocation),
                ELogGroup.Equipment, ESeverityLog.Error);
        }
    } catch (Exception e) {
        m_logger.AddErrHandler(e);
    }
};

m_server.CommandReceived += onCommandReceivedDlg;

msg.SendRequestDateTime = DateTime.Now;
m_server.SendMessage(ref iSocket, ref message);
if (!msgResponseWait.WaitOne(msg.TimeoutResponseInMillis)) {
    m_logger.AddTrace("No response received", ELogGroup.Equipment, ESeverityLog.Error);
    msg.TimeoutOccurred = true;
}

m_server.CommandReceived -= onCommandReceivedDlg;

msg.WaitResponse.Set();

}

感谢您的帮助

手动对于ManualResetEvent.Set（）

0 个答案: