ASP.Net ThreadPool委托回调——JavaScript不会在回调线程上触发

它不会在JS中触发，因为你正在旋转一个新线程。与此同时，请求早已返回到客户端并关闭了连接。当线程尝试向响应写入一些内容时，它已经完成了。

而不是这样做，只是有你的按钮点击(或任何它是启动报告)，在UpdatePanel内。这样，就不需要启动新线程了。

Here is the cod I used in the C# Code Behind to call the web service to start monitoring this process.
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                CurrentSession.bIsReportRunning = true;
                ScriptManager.RegisterStartupScript(this, this.GetType(), "WaitForReport" + DateTime.Now.ToString(), "jsWaitOnCallReport();", true);
                MultiThreadReport.RunTheReport(HttpContext.Current, CurrentSession, this, oBRO);
Here is the code that calls the method, using the threadpool, and the method called..
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            ThreadPool.QueueUserWorkItem(new WaitCallback(StartReport), cts.Token);
    public static void StartReport(object obj) {
        try {
            OnTaskCompleteDelegate callback = new OnTaskCompleteDelegate(OnTaskComplete);
            BoyceReporting.CallReport(boyce.BoyceThreadingEnvironment.OBRO, "THREADING");
            HttpContext.Current = boyce.BoyceThreadingEnvironment.CONTEXT;
            if (boyce.BoyceThreadingEnvironment.CTS.Token.IsCancellationRequested) {
                boyce.BoyceThreadingEnvironment.SESSION.sScriptToExecute = "alert('Report Canceled By User');";
                boyce.BoyceThreadingEnvironment.SESSION.bIsReportRunning = false;
                callback("CANCELED");
            } else {
                boyce.BoyceThreadingEnvironment.SESSION.bIsReportRunning = false;
                callback("FINISHED");
            }
        } catch {
            throw;
        }
    }
Here is the web service method I created to monitor the process, with a built in safety net
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    [WebMethod(EnableSession = true)]
    public string WaitOnReport() {
        try {
            HttpContext.Current = boyce.BoyceThreadingEnvironment.CONTEXT;
            SessionManager CurrentSession;
            CurrentSession = (SessionManager)boyce.BoyceThreadingEnvironment.SESSION;
            DateTime dtStartTime = DateTime.Now;
            DateTime dtCurrentTime = DateTime.Now;
            if (CurrentSession != null) {
                do {
                    //  Build a safety limit into this loop to avoid an infinate loope
                    //  If this runs longer than 20 minutes, then force an error due to timeout
                    //  This timeout should be lowered when they find out what the issue is with 
                    //  the "long running reports".  For now, I set it to 20 minutes but shoud be MUCH lower.
                    dtCurrentTime = DateTime.Now;
                    TimeSpan span = dtCurrentTime-dtStartTime;
                    double totalMinutes = span.TotalMinutes;
                    if (totalMinutes>=20) {
                        return "alert('Error In Creating Report (Time-Out)');";
                    }
                } while (CurrentSession.bIsReportRunning == true);
                //  If all goes well, return the script to either OPEN the report or display CANCEL message
                return CurrentSession.sScriptToExecute;
            } else {
                return "alert('Error In Creating Report (Session)');";
            }
        } catch {
            throw;
        }
    }

And here is the JavaScript code I used to initiate the Web Service Call and Also The Postback
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function jsWaitOnCallReport() {
    try {
        var oWebService = BoyceWebService.WaitOnReport(jsWaitOnCallReport_CallBack);
    } catch (e) {
        alert('Error In Calling Report Screen -- ' + e);
    }
}
function jsWaitOnCallReport_CallBack(result) {
    try {
        eval(result); 
        var myExtender = $find('ModalPopupExtenderPROGRESS');
        if (myExtender != null) {
            try {
                myExtender.hide();
            } catch (e) {
                //  Ignore Any Error That May Be Thrown Here
            }
        }
        $find('PROGRESS').hide();
    } catch (e) {
        alert('Error In Opening Report Screen -- ' + e);
    }
}
Hope this helps someone else out..  Like I said, I am not sure this is the best solution, but it works..   I would be interested in other solutions for this issue to try...  Thanks.