同时处理多个呼叫的问题

Question

private void Recorder_ExecuteCode(object sender, EventArgs e)
    {
        fileName = "";
        SendMail = false;
        CallIsAlive = true;
        Recorder recorder = new Recorder();

        // Use the call ID as the filename and create a media sink.
        Random rnd = new Random();
        fileName = string.Format("C:\\recordings\\Inbound Call\\EmergencyCall {0}.wma", DateTime.Now.Day.ToString() + "." + DateTime.Now.Month.ToString() + "." + DateTime.Now.Year.ToString() + " - " + DateTime.Now.Hour.ToString() + "." + DateTime.Now.Minute.ToString() + "." + DateTime.Now.Second.ToString() + rnd.Next().ToString());
        WmaFileSink fileSink = new WmaFileSink(fileName);
        Console.WriteLine("Recording for 10 seconds.");

        // Set the recorder to use the media sink and attach
        // it to the flow.
        recorder.SetSink(fileSink);
        recorder.AttachFlow(Program.MyCall.Flow);


        // Start recording.

        recorder.Start();
        SendMail = true;
    }

上面的代码设置了一个附加到入站呼叫的audiovideoflow的记录器。

我遇到的问题是，如果同时进入2个调用并尝试调用Recorder_executeCode函数，程序将崩溃：

        recorder.AttachFlow(Program.MyCall.Flow);

Visual Studio报告以下错误：

用户代码未处理InvalidOperationException。 AudioVideoFlow已绑定到记录器。

如果两个或多个呼叫者同时呼叫，我将如何更改代码以允许同时运行多个功能副本。

修改

问题是由使用全局变量引起的：MyCall

我通过使用Call.CallId

设置文件名字符串来解决问题

 private void Recorder_ExecuteCode(object sender, EventArgs e)
    {
        string fileName;
        SendMail = false;
        Recorder recorder = new Recorder();

        // Use the call ID as the filename and create a media sink.
        //Random rnd = new Random();
        fileName = string.Format("C:\\recordings\\Inbound Call\\EmergencyCall {0}.wma", acceptCallActivityInboundCall1.CallProvider.ToneController.AudioVideoFlow.Call.CallId.ToString());
        WmaFileSink fileSink = new WmaFileSink(fileName);
        Console.WriteLine("Recording for 10 seconds.");


        // Set the recorder to use the media sink and attach
        // it to the flow.
        recorder.SetSink(fileSink);
        recorder.AttachFlow(acceptCallActivityInboundCall1.CallProvider.ToneController.AudioVideoFlow);


        // Start recording.

        recorder.Start();
        SendMail = true;
    }