返回数据后如何继续执行方法？

Question

我开发了一个用于机器性能监控的 Web API，当通过 URL 调用资源时，信息以 json 格式打印在浏览器上。其中一种方法有一个循环，每秒获取一个新的数据值。

是否可以在每次迭代时“返回”该值并在浏览器上以 json 格式显示，从而在每次迭代时自动更新？换句话说，我是在尝试创建一个实时更新机制，而不是等待程序执行，然后在性能数据日志完成后显示 json。

public List<LogInfo> LogTimedPerfData(string macName, string categoryName, string counterName,
                                          string instanceName, string logName, long? seconds)
    {
        iModsDBRepository modsDB = new iModsDBRepository();
        List<MachineInfo> theMac = modsDB.GetMachineByName(macName);

        if (theMac.Count == 0)
            return new List<LogInfo>();

        else if (instanceName == null)
        {
            if (!PerformanceCounterCategory.Exists(categoryName, macName) ||
                !PerformanceCounterCategory.CounterExists(counterName, categoryName, macName) )
            {
                return new List<LogInfo>();
            }
        }
        else if (instanceName != null)
        {
            if (!PerformanceCounterCategory.Exists(categoryName, macName) ||
                !PerformanceCounterCategory.CounterExists(counterName, categoryName, macName) ||
                !PerformanceCounterCategory.InstanceExists(instanceName, categoryName, macName))
            {
                return new List<LogInfo>();
            }
        }
        else if (logName == null)
        {
            return new List<LogInfo>();
        }

        // Check if entered log name is a duplicate for the authenticated user
        List<LogInfo> checkDuplicateLog = this.GetSingleLog(logName);
        if (checkDuplicateLog.Count > 0)
        {
            return new List<LogInfo>();
        }

        PerformanceCounterCategory category = new PerformanceCounterCategory(categoryName, theMac[0].MachineName);
        if (category.CategoryName == null || category.MachineName == null)
        {
            return new List<LogInfo>();
        }

        List<LogInfo> logIt = new List<LogInfo>();
        if (category.CategoryType != PerformanceCounterCategoryType.SingleInstance)
        {
            List<InstanceInfo> instances = modsDB.GetInstancesFromCatMacName(theMac[0].MachineName, category.CategoryName);

            foreach (InstanceInfo inst in instances)
            {
                if (!category.InstanceExists(inst.InstanceName))
                {
                    continue;
                }
                else if (inst.InstanceName.Equals(instanceName, StringComparison.OrdinalIgnoreCase))
                {
                    PerformanceCounter perfCounter = new PerformanceCounter(categoryName, counterName,
                                                                        inst.InstanceName, theMac[0].MachineName);

                    string data = "";
                    List<UserInfo> currUser = this.GetUserByName(WindowsIdentity.GetCurrent().Name);

                    string timeStarted = DateTime.Now.ToString("MM/dd/yyyy - h:mm:ss tt");

                    string[] dataValues = new string[(int)seconds];
                    for (int i = 0; i < seconds; i++)
                    {
                        data = "Value " + i + ": " + perfCounter.NextValue().ToString();
                        dataValues[i] = data;
                        Thread.Sleep(1000);
                    }
                    string timeFinished = DateTime.Now.ToString("MM/dd/yyyy - h:mm:ss tt");

                    Log log = new Log
                    {
                        LogName = logName,
                        CounterName = perfCounter.CounterName,
                        InstanceName = perfCounter.InstanceName,
                        CategoryName = perfCounter.CategoryName,
                        MachineName = perfCounter.MachineName,
                        TimeStarted = timeStarted,
                        TimeFinished = timeFinished,
                        PerformanceData = string.Join(",", dataValues),
                        UserID = currUser[0].UserID
                    };
                    this.CreateLog(log);
                    logIt.Add(new LogInfo
                    {
                        LogName = logName,
                        CounterName = perfCounter.CounterName,
                        InstanceName = perfCounter.InstanceName,
                        CategoryName = perfCounter.CategoryName,
                        MachineName = perfCounter.MachineName,
                        TimeStarted = timeStarted,
                        TimeFinished = timeFinished,
                        PerformanceData = dataValues.ToList<string>()
                    });
                    break;
                }
            }
        }
        else
        {
            PerformanceCounter perfCounter = new PerformanceCounter(categoryName, counterName,
                                                                        "", theMac[0].MachineName);


            string data = "";
            List<UserInfo> currUser = this.GetUserByName(WindowsIdentity.GetCurrent().Name);

            string timeStarted = DateTime.Now.ToString("MM/dd/yyyy - h:mm:ss tt");

            string[] dataValues = new string[(int)seconds];
            for (int i = 0; i < seconds; i++)
            {
                data = "Value " + i + ": " + perfCounter.NextValue().ToString();
                dataValues[i] = data;
                Thread.Sleep(1000);
            }
            string timeFinished = DateTime.Now.ToString("MM/dd/yyyy - h:mm:ss tt");

            Log log = new Log
            {
                LogName = logName,
                CounterName = perfCounter.CounterName,
                InstanceName = perfCounter.InstanceName,
                CategoryName = perfCounter.CategoryName,
                MachineName = perfCounter.MachineName,
                TimeStarted = timeStarted,
                TimeFinished = timeFinished,
                PerformanceData = string.Join(",", dataValues),
                UserID = currUser[0].UserID
            };              
            this.CreateLog(log);
            logIt.Add(new LogInfo
            {
                LogName = logName,
                CounterName = perfCounter.CounterName,
                InstanceName = perfCounter.InstanceName,
                CategoryName = perfCounter.CategoryName,
                MachineName = perfCounter.MachineName,
                TimeStarted = timeStarted,
                TimeFinished = timeFinished,
                PerformanceData = dataValues.ToList<string>()
            });
        }
        return logIt;
    }

Answer 1

您可能想对SignalR 进行一些研究，那里有一些关于使用 SignalR 向浏览器推送通知的教程。

一些可能有用的链接：

• https://github.com/SignalR/SignalR/wiki
• http://www.codeproject.com/Articles/322154/ASP-NET-MVC-SIngalR-and-Knockout-based-Real-time-U
• http://www.msguy.com/2011/11/real-time-push-notifications-with.html