实时获取CPU使用率(网上找的，仅自用，非原创)

using System;
using System.Diagnostics;
using System.Threading;

public class CpuLoadInfo
{
// auxiliary print methods
private static void Say(string txt)
{
Console.WriteLine(txt);
}

// auxiliary print methods
private static void Say()
{
Say("");
}

// The main method. Command line arguments are ignored.

public static void Main()
{
Say("$Id: CpuLoadInfo.cs,v 1.2 2002/08/17 17:45:48 rz65 Exp $");
Say();
Say("Attempt to create a PerformanceCounter instance:");
Say("Category name = " + CategoryName);
Say("Counter name = " + CounterName);
Say("Instance name = " + InstanceName);

PerformanceCounter pc = new PerformanceCounter(CategoryName,CounterName,InstanceName);
Say("Performance counter was created.");
Say("Property CounterType: " + pc.CounterType);
Say();
Say("Property CounterHelp: " + pc.CounterHelp);
Say();
Say("Entering measurement loop.");

while(true)
{
Thread.Sleep(1000); // wait for 1 second
float cpuLoad = pc.NextValue();
Say("CPU load = " + cpuLoad + " %.");
}
}

// constants used to select the performance counter.
private const string CategoryName = "Processor";
private const string CounterName = "% Processor Time";
private const string InstanceName = "_Total";
}