对于那些仍然无法获得与任务管理器匹配的CPU使用总数的人，您应该使用以下语句:

new PerformanceCounter("Processor Information", "% Processor Utility", "_Total");

您可以使用System.Diagnostics中的PerformanceCounter类。

像这样初始化:

PerformanceCounter cpuCounter;
PerformanceCounter ramCounter;

cpuCounter = new PerformanceCounter("Processor", "% Processor Time", "_Total");
ramCounter = new PerformanceCounter("Memory", "Available MBytes");

这样消费:

public string getCurrentCpuUsage(){
            return cpuCounter.NextValue()+"%";
}

public string getAvailableRAM(){
            return ramCounter.NextValue()+"MB";
} 

public int GetCpuUsage()
{
    var cpuCounter = new PerformanceCounter("Processor", "% Processor Time", "_Total", Environment.MachineName);
    cpuCounter.NextValue();
    System.Threading.Thread.Sleep(1000); //This avoid that answer always 0
    return (int)cpuCounter.NextValue();
}

原始信息在此链接https://gavindraper.com/2011/03/01/retrieving-accurate-cpu-usage-in-c/

比要求的多一点，但我使用额外的计时器代码来跟踪和警报，如果CPU使用率在持续1分钟或更长时间内达到90%或更高。

public class Form1
{

    int totalHits = 0;

    public object getCPUCounter()
    {

        PerformanceCounter cpuCounter = new PerformanceCounter();
        cpuCounter.CategoryName = "Processor";
        cpuCounter.CounterName = "% Processor Time";
        cpuCounter.InstanceName = "_Total";

                     // will always start at 0
        dynamic firstValue = cpuCounter.NextValue();
        System.Threading.Thread.Sleep(1000);
                    // now matches task manager reading
        dynamic secondValue = cpuCounter.NextValue();

        return secondValue;

    }


    private void Timer1_Tick(Object sender, EventArgs e)
    {
        int cpuPercent = (int)getCPUCounter();
        if (cpuPercent >= 90)
        {
            totalHits = totalHits + 1;
            if (totalHits == 60)
            {
                Interaction.MsgBox("ALERT 90% usage for 1 minute");
                totalHits = 0;
            }                        
        }
        else
        {
            totalHits = 0;
        }
        Label1.Text = cpuPercent + " % CPU";
        //Label2.Text = getRAMCounter() + " RAM Free";
        Label3.Text = totalHits + " seconds over 20% usage";
    }
}

对于那些仍然无法获得与任务管理器匹配的CPU使用总数的人，您应该使用以下语句:

new PerformanceCounter("Processor Information", "% Processor Utility", "_Total");

在花了一些时间阅读了几个看起来相当复杂的不同线程后，我想到了这个。我需要它为一个8核的机器，我想监视SQL server。对于下面的代码，我将“sqlservr”作为appName传入。

private static void RunTest(string appName)
{
    bool done = false;
    PerformanceCounter total_cpu = new PerformanceCounter("Process", "% Processor Time", "_Total");
    PerformanceCounter process_cpu = new PerformanceCounter("Process", "% Processor Time", appName);
    while (!done)
    {
        float t = total_cpu.NextValue();
        float p = process_cpu.NextValue();
        Console.WriteLine(String.Format("_Total = {0}  App = {1} {2}%\n", t, p, p / t * 100));
        System.Threading.Thread.Sleep(1000);
    }
}

它似乎正确地测量了我的8核服务器上SQL所使用的CPU百分比。