使用C＃检索系统正常运行时间

Question

有没有一种简单的方法可以使用C＃获得系统的正常运行时间？

Answer 1

public TimeSpan UpTime {
    get {
        using (var uptime = new PerformanceCounter("System", "System Up Time")) {
            uptime.NextValue();       //Call this an extra time before reading its value
            return TimeSpan.FromSeconds(uptime.NextValue());
        }
    }
}

Answer 2

我有点迟了，但另一种简单方式是使用GetTickCount64函数，该函数从Windows Vista开始可用，并且不像GetTickCount那样溢出：

public static TimeSpan GetUpTime()
{
    return TimeSpan.FromMilliseconds(GetTickCount64());
}

[DllImport("kernel32")]
extern static UInt64 GetTickCount64();

Answer 3

System.Environment.TickCount获取自系统重启以来的毫秒数。

请注意，它是一个Int32，并会在24.9天后溢出并且会变为负数。请参阅MDSN文档上的备注。

Answer 4

根据任务经理的说法，我的机器的正常运行时间为58 days 17 hours。我经历过并尝试了每个答案，而快速的答案有点偏差（约1-3分钟，但超过58天的正常运行时间）：

Stopwatch.GetTimeStamp():                   58days 17hours 11minutes 25seconds
~Time to calculate (ms): 6.8413
DllImport GetTickCount64():                 58days 17hours 13minutes 34seconds
~Time to calculate (ms): 0.2192
PerformanceCounter(System, System Up Time): 58days 17hours 14minutes 02seconds
~Time to calculate (ms): 1233.2854
ManagementObject LastBootUpTime:            58days 17hours 14minutes 02seconds
~Time to calculate (ms): 30.0283

最后两个，使用PerformanceCounter或使用ManagementObject，始终与Windows任务管理器在同一秒内（只需要接受我的话，或者使用下面的代码自己尝试）。根据结果​​，我将使用ManagementObject LastBootUpTime方法，因为它比PerformanceCounter快得多，但与任务管理器相比仍然非常准确。

请注意，我确实在打印时间之前从每个方法中减去当前经过的时间，但是整个过程花费的时间不到2秒，因此无论如何都不能通过不正确地计算执行时间来解释时移。这是我使用的代码：

[System.Runtime.InteropServices.DllImport("kernel32")]
extern static UInt64 GetTickCount64();

public static void Main()
{
    var start = Stopwatch.StartNew();

    var eachStart = Stopwatch.StartNew();
    var ticks = Stopwatch.GetTimestamp();
    var uptime = ((double)ticks) / Stopwatch.Frequency;
    var uptimeTimeSpan = TimeSpan.FromSeconds(uptime);
    Console.WriteLine("Stopwatch.GetTimeStamp():                   " + uptimeTimeSpan.Subtract(start.Elapsed).ToString(@"dd\d\a\y\s\ hh\h\o\u\r\s\ mm\m\i\n\u\t\e\s\ ss\s\e\c\o\n\d\s"));
    Console.WriteLine($"~Time to calculate (ms): {eachStart.Elapsed.TotalMilliseconds}");

    eachStart.Restart();
    Console.WriteLine("DllImport GetTickCount64():                 " + TimeSpan.FromMilliseconds(GetTickCount64()).Subtract(start.Elapsed).ToString(@"dd\d\a\y\s\ hh\h\o\u\r\s\ mm\m\i\n\u\t\e\s\ ss\s\e\c\o\n\d\s"));
    Console.WriteLine($"~Time to calculate (ms): {eachStart.Elapsed.TotalMilliseconds}");

    eachStart.Restart();
    var upTime = new PerformanceCounter("System", "System Up Time");
    upTime.NextValue();       //Call this an extra time before reading its value
    Console.WriteLine("PerformanceCounter(System, System Up Time): " + TimeSpan.FromSeconds(upTime.NextValue()).Subtract(start.Elapsed).ToString(@"dd\d\a\y\s\ hh\h\o\u\r\s\ mm\m\i\n\u\t\e\s\ ss\s\e\c\o\n\d\s"));
    Console.WriteLine($"~Time to calculate (ms): {eachStart.Elapsed.TotalMilliseconds}");

    eachStart.Restart();
    ManagementObject mo = new ManagementObject(@"\\.\root\cimv2:Win32_OperatingSystem=@");
    DateTime lastBootUp = ManagementDateTimeConverter.ToDateTime(mo["LastBootUpTime"].ToString());
    Console.WriteLine("ManagementObject LastBootUpTime:            " + (DateTime.Now.ToUniversalTime() - lastBootUp.ToUniversalTime()).Subtract(start.Elapsed).ToString(@"dd\d\a\y\s\ hh\h\o\u\r\s\ mm\m\i\n\u\t\e\s\ ss\s\e\c\o\n\d\s"));
    Console.WriteLine($"~Time to calculate (ms): {eachStart.Elapsed.TotalMilliseconds}");
}

Answer 5

精确且大于System.Environment.TickCount，不涉及操作系统可怕的性能计数器，WMI或本机调用：

var ticks = Stopwatch.GetTimestamp();
var uptime = ((double)ticks) / Stopwatch.Frequency;
var uptimeSpan = TimeSpan.FromSeconds(uptime);

Answer 6

最简单和正确的方法是

public static TimeSpan GetUptime()
{
    ManagementObject mo = new ManagementObject(@"\\.\root\cimv2:Win32_OperatingSystem=@");
    DateTime lastBootUp = ManagementDateTimeConverter.ToDateTime(mo["LastBootUpTime"].ToString());
    return DateTime.Now.ToUniversalTime() - lastBootUp.ToUniversalTime();
}

Answer 7

简单，不，但可以做到：

    static DateTime getLastBootTime(ManagementObject mObject)
    {
        PropertyData pd = mObject.Properties["LastBootUpTime"];
        string name = pd.Name.ToString();
        DateTime lastBoot = parseCmiDateTime(pd.Value.ToString());
        return lastBoot;
    }

    static ManagementObject getServerOSObject(string serverName)
    {
        ManagementObjectSearcher mSearcher = new ManagementObjectSearcher("Select * From Win32_OperatingSystem");
        mSearcher.Scope = new ManagementScope(String.Format(@"\\{0}\root\cimv2", serverName));
        ManagementObjectCollection mObjects = mSearcher.Get();
        if (mObjects.Count != 1) throw new Exception(String.Format("Expected 1 object, returned {0}.", mObjects.Count));
        foreach (ManagementObject m in mObjects)
        {
            //No indexing on collection
            return m;
        }
        throw new Exception("Something went wrong!");
    }

Answer 8

如果您使用的是更高版本的 .NET（Core 3.0/.NET 5.0 或更高版本），那么 Environment 类现在有一个 TickCount64 property。

这不会受到 TickCount 属性的环绕问题的影响，您也不必求助于 P/Invoke 来获取值。

long tickCountMs = Environment.TickCount64;
var uptime = TimeSpan.FromMilliseconds(tickCountMs);

Answer 9

我知道问题既旧又解决了，但我能说的最好的解决办法就是使用Enviroment.TickCount属性，该属性返回自系统启动以来的毫秒数：

System.DateTime SystemStartTime = DateAndTime.Now.AddMilliseconds(-Environment.TickCount);
System.DateTime Uptime = DateAndTime.Now - SystemStartTime;

这个解决方案比被接受的answare快得多。

Answer 10

到目前为止（唯一的）正确答案：

使用32位计时器非常危险，除了有限的使用外，所有其他地方都容易出错。

我不确定何时将NativeMethods类的内容添加到.net，但确实如此。您绝对想避免P / Invoke开销。这样做：

using System;
using System.Runtime.InteropServices;

namespace Mu
{

    // prevents PInvoke (not in NativeMethods class) or Stack walk (NativeMethods class) performance penalties.
    internal static partial class SafeNativeMethods
    {
        [DllImport("kernel32")]
        internal extern static UInt64 GetTickCount64();

    }
    public static class MuTime
    {
        public static UInt64 UpTimeMillis {  get { return SafeNativeMethods.GetTickCount64();  } }
    }
}

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